Photorhabdus, has been studied by heterologous expression of the photopyrone synthase PpyS catalyzing the head-to-head condensation of two acyl moieties. The biochemical mechanism of pyrone formation has been investigated by amino acid exchange and bioinformatic analysis. Additionally, the evolutionary origin of PpyS has been studied by phylogenetic analyses also revealing homologous enzymes in Pseudomonas sp. GM30 responsible for the biosynthesis of pseudopyronines including a novel derivative. Moreover this novel class of ketosynthases is only distantly related to other pyrone-forming enzymes identified in the biosynthesis of the potent antibiotics myxopyronin and corallopyronin.The biosynthesis of photopyrones, novel quorum sensing signals in  Photorhabdus luminescens. The system consists of endogenously produced photopyrones as signaling molecules and PluR, a LuxR-like receptor [pcfABCDEF) that causes clumping of cells and results in insect toxicity [Chemical compounds containing an α-pyrone moiety are widespread in nature –2 and shreceptor . The bintoxicity . ResponsPhotorhabdus asymbiotica [Xanthomonas campestris by promoting a head-to-head condensation of two long-chain fatty acid thioesters to form a long-chain β-ketoacid that can be further processed to an olefin [Ketosynthases (KS) are the key enzymes involved in the biosynthesis of fatty acids and polyketides . They armbiotica . A furthn olefin . KS withn olefin , xenocyln olefin  and nonan olefin .plu4844 encoding the ketosynthase PpyS in P. luminescens resulted in the complete loss of photopyrone production as shown previously [ppyS, bkdABC and ngrA in E. coli allowed the reconstitution of photopyrone production: Coexpression of genes encoding the branched chain α-ketoacid dehydrogenase (Bkd) complex of P. luminescens (BkdABC) was required for the production of iso-fatty acids [Plasmid integration into the gene eviously . Additioty acids , whereasty acids .14 is covalently bound to an active site cysteine. Deprotonation of the α-carbon of 14 results in the formation of a nucleophile, which subsequently attacks the carbonyl carbon of a 5-methyl-3-oxohexanoyl thioester 15, formed by BkdABC [16 the α-pyrone ring is formed and 4 is released from PpyS. The two substrates 14 and 15 might be either ACP (acyl carrier protein) or CoA (coenzyme A) bound thioesters depending whether they originate from fatty acid biosynthesis or degradation, respectively. Due to the variability of the first substrate regarding chain length and starting unit, the different photopyrones A–H (1–8) are produced. We assume that in the second deprotonation step, the deprotonation can either occur spontaneously, due to the two neighboring carbonyl groups or it can be enzyme catalyzed.Usually pyrones are derived in a one-chain mechanism from type III polyketide synthases ,19 rarely BkdABC  to form P. luminescens, we decided to generate a homology model for PpyS as no crystal structure could be obtained due to low expression levels under all conditions tested. The homodimeric structure of OleA from Xanthomonas campestris, showing the highest sequence identity (27%) of all available crystal structures at the PDB [To investigate the photopyrone biosynthesis in  the PDB , was use14 and 16  responsible for the covalent binding of the fatty acid precursor, as well as amino acids present at the dimer interface  and B (10) have been isolated in two Pseudomonas strains but neither their biosynthesis nor the involved KS had been reported yet [Pseudomonas sp. GM30 is producing pseudopyronine A (9), B (10) and the new derivative C (11) all differing in the chain length of the eastern acyl moiety. As heterologous expression of the proposed KS from strain GM30 in E. coli did not result in the production of 9–11 or a similar derivative, heterologous expression was tested in Pseudomonas putida KT2440 as well as homologous expression in Pseudomonas sp. GM30. In both experiments production of 9–11 was observed  is responsible for pseudopyronine biosynthesis. The homology model for PyrS (Figure S8, 17 and intermediate 19 to the active site C124 also confirmed the glutamic acid inside the binding pocket as catalytically important suggesting a biosynthesis model (Scheme S1, Pseudomonas strains, which are generally rich in cell–cell communication signals [In order to prove that the identified PpyS homologues are indeed involved in pyrone biosynthesis we analyzed the KS from rted yet . Both corted yet . Natural signals –35.In summary we have shown that two unusual ketosynthases are responsible for the formation of photopyrones and pseudopyronines. Furthermore, we have confirmed the PpyS mechanism by mutagenesis and through detailed phylogenetic analysis we could show that PpyS and homologous KS do form a new branch in the KS phylogenetic tree that is more distant to other pyrone forming KS as found in the biosynthesis of the potent antibiotics myxopyronin and corallopyronin.File 1Experimental procedures, details of bioinformatic analysis and NMR data of pseudopyronines.


Background. Hearing aids sold directly to consumers in retail stores or through the internet, without individual prescription by audiological professionals, are termed over-the-counter (OTC) devices. This study aimed to determine whether there was any change in the electroacoustic characteristics of OTC devices compared to research carried out a decade earlier. The previous results indicated that most OTC devices were low-frequency-emphasis devices and were unsuitable for elderly people with presbycusis, who were likely to be the major consumers of these products. Methods. Ten OTC devices were selected and their electroacoustic performance was measured. Appropriate clients for the OTC devices were derived, using four linear prescription formulae, and OTC suitability for elderly persons with presbycusis was investigated. Results. OTC electroacoustic characteristics were similar to those in the earlier study. Most OTC devices were not acoustically appropriate for potential consumers with presbycusis. Although several of the devices could match prescriptive targets for individuals with presbycusis, their poor electroacoustic performance—including ineffective volume control function, high equivalent input noise, and irregular frequency response—may override their potential benefit. Conclusion. The low-cost OTC devices were generally not suitable for the main consumers of these products, and there has been little improvement in the appropriateness of these devices over the past decade. Hearing aids that are sold directly to consumers in retail shops or through the internet, without customized prescription by audiological professionals, are termed over-the-counter (OTC) hearing aids , 2. PeopIn many developed economies, the sale of hearing aids is regulated. For example, in the United States, the provision of hearing aids is under the regulation of the United States Food and Drug Administration. Only licensed hearing healthcare professionals can provide hearing aids. Purchasers have to show a recent medical statement proving that they are hearing aid candidates or sign a waiver stating that they declined medical evaluation of their hearing loss before receiving the hearing aids . These rAn informal survey conducted in Hong Kong by Cheng  indicatePresbycusis is a very common problem in the elderly population in both developed and developing countries . AccordiElderly people are likely to be the major users of OTC hearing aids. However, previous literature indicates that the quality of the OTC hearing aids and their effectiveness in matching the amplification needs of elderly people with presbycusis may be questionable.Two previous studies, one undertaken in Hong Kong (Cheng and McPherson)  and one Most of the low-cost OTC hearing aids investigated in previous studies were low-frequency emphasis hearing aids with little gain or even no gain in high frequencies , 2. TherEIN is the internal electronic noise of the hearing aid and it becomes audible and disturbing if it is too high . Some ofTHD reflects the amount of harmonic distortion generated by a hearing aid . The THDCheng and McPherson , 2 reporAll of the above electroacoustic characteristics of OTC hearing aids were based on low-cost models retailing for less than US$100 each. The electroacoustic performance of some higher cost OTC hearing aids may be more suitable to people with presbycusis .Previously studied low-cost OTC hearing aids generally were incapable of providing sufficient appropriate gain to elderly people with presbycusis and their overall electroacoustic performance was not satisfactory , 2. HoweThe present study aimed to determine whether there was any change in the electroacoustic characteristics of OTC hearing aids available in Hong Kong over the past decade. The electroacoustic performance of the current generation of OTC hearing aids in Hong Kong was examined. In addition, the study also aimed to determine the potential client groups for the OTC hearing aids and whether recent OTC hearing aids are appropriate for elderly people with presbycusis. The results obtained may have important implications for those who plan to purchase OTC hearing aids and for audiologists and other hearing health professionals advising patients with hearing impairment.Ten low-cost OTC hearing aids were investigated in present study. Selection was based on their wide availability to consumers in rehabilitation aid stores, electrical appliance shops and department stores in Hong Kong. The study had three aspects: 1) Measurement of the electroacoustic performance of the OTC hearing aids. Both 2-cc coupler measurement and simulated real-ear measurement were conducted to examine the performance of the OTC hearing aids; (2) Estimation of the hearing loss that could be appropriately fitted with the OTC hearing aids using four prescriptive formulae. The four prescriptive formulas used in present study were the National Acoustic Laboratories-Revised (NAL-R), prescription of gain and output (POGO), Libby one-third gain (Libby 1/3) and Desired Sensation Level 4.0 (DSL 4.0); and (3) Determination of whether the OTC hearing aids could be appropriately fit to adults with typical sensorineural hearing loss caused by presbycusis, using the NAL-R prescriptive formula. The NAL-R formula was selected because this formula is a relatively widely used method among linear prescriptive formulae  Measurem. For comThe ten OTC hearing aids investigated in the present study were (A) LingYin HA 611B; (B) Hopewell HAP-40; (C) Axwa EX-12D; (D) JNC-MHA-BTE130; (E) UP-6411; (F) ShengDe V-163; (G) Axwa OM-188; (H) Powertone HAP-F883; (I) JNC-MHA-ITE 110; and (J) Axon K-80. All of them were low-cost OTC hearing aids costing less than US$115 each. Moreover, they were not investigated in a previous OTC hearing aid study in Hong Kong [Each OTC hearing aid was provided with, on average, three stock ear domes of different sizes by the manufacturer. The outer diameter of the domes ranged from 0.7 to 1.3 cm, with a dome with outer diameter of 1.0 cm being the most commonly available size. To standardize the measurements, domes with outer diameter of 1.0 cm or the nearest available size were used in the electroacoustic measurements.All of the electroacoustic measurements were conducted with a Fonix 7000 Hearing Aid Test System in a Fonix 7020 sound chamber . An HA-1 coupler was used in the 2-cc coupler measurement, as an HA-1 coupler is recommended to measure hearing aids with attached molds . Using KBoth 2-cc coupler and simulated real-ear measurements were performed. In the 2-cc coupler measurements, the OTC hearing aids were tested according to the ANSI S3.22-2009 hearing aid specification standard .In addition, the output sound pressure level and the gain at different volume settings were measured. The volume control wheels of the hearing aids were divided into 4 equal portions and the gains were measured at the starting, 1/4, 1/2, 3/4, and the full-on positions [In the simulated real-ear feedback measurements, the hearing aids were tested on KEMAR's right pinna. The loudspeaker was located at an azimuth angle of 45° and 30 cm from KEMAR . The cenThe hypothetical hearing losses that could be appropriately prescribed with the OTC hearing aids were estimated. These estimates were based on the 2-cc coupler gain at the full-on position for each device and were derived using four prescription formulae .The average hearing thresholds of elderly people were estimated based on the study by Stenklev and Laukli , who surTarget 2-cc coupler full-on gains were generated by the NAL-R prescription formula based on the estimated average hearing thresholds of an elderly person shown in 2-cc coupler measurement results for the ten OTC hearing aids are summarized in All OTC hearing aid frequency response curves showed high frequency limits up to 4000 Hz, except for OTC C , D, and F. The shape of the frequency response curve for OTC B differed from that usually found in hearing aids. The OSPL 90 curves and frequency response curves of three OTC hearing aids  are shown in All of the OTC hearing aids investigated were linear hearing aids and most of them showed peak clipping at high input levels. Volume control characteristics are shown in In the feedback measurement, none of the OTC hearing aids exhibited feedback problems even at a full-on volume position.t-test analysis. In these four parameters, the input signals used in measuring HFA FOG and EIN are different between ANSI 3.22-1987 and ANSI 3.22-2009 standards. Nevertheless, the gain measured with either 60 dB in ANSI 3.22-1987 or 50 dB in ANSI 3.22-2009 is the same for linear hearing aids. Therefore, comparison can be made between the two studies. The results are presented in p > 0.05) in these parameters between the present study and the previous Hong Kong OTC hearing aid study.The peak frequency and peak sound pressure level at OSPL 90, the HFA FOG, and EIN in the present study were compared with those parameters in Cheng and McPherson's study  using anThe hypothetical hearing losses estimated by the four prescription formulae when using the 2-cc coupler full-on gain data were plotted for each OTC hearing aid and are shown in Most of the OTC hearing aids showed their peak response at the mid frequencies, while OTC B, H, and J had their maximum response at the low frequencies. Excessive amplification in the low frequencies will increase the adverse effects of background noise and additionally increase the possibility of upward spread of masking by low-frequency speech components . Hence, Despite most OTC hearing aids having a frequency range up to 4000 Hz, there was little or no usable gain at or above 4000 Hz. Some frequency responses dropped abruptly at about 4000 Hz, such as OTC A (tone N and tone L), OTC E, and OTC I. In the present study, all the BTE and ITE hearing aids examined could not provide adequate high frequency amplification. BW was the only style that could provide 15 dB or more gain at 4000 Hz.Narrow peaks with approximately 10 dB amplitude were observed in the high frequency region of the frequency responses for OTC A (tone N and tone L), OTC D, OTC E, and OTC F. According to Dillon and Macrae  and van The HFA FOG was generally higher in the BW styles and lower in the ITE styles. The mean HFA FOG was 43.3 dB in BW, 29.9 dB in BTE, and 14.2 dB in ITE hearing aids. HFA FOG is the average FOG at 1000 Hz, 1600 Hz, and 2500 Hz and is used in the ANSI standard because these frequencies are very important for speech intelligibility and because most hearing aids generate significant amount of gain at these frequencies . HoweverAll of the OTC hearing aids investigated were linear hearing aids and most of them showed peak clipping at high input levels. As mentioned before, linear hearing aids are often not suitable for people with sensorineural hearing loss . MoreoveIn the present results, the EIN ranged from 24.9 to 52.9 dB SPL, with a mean value of 33.1 dB SPL. The extremely high EINs found in OTC J and OTC H were probably measurement artifacts due to their low HAF gain . AccordiTHD values below 5% and not more than 10% were recommended by Dillon and Macrae . Most ofThe estimated battery life of all the OTC hearing aids was acceptable, ranging from 142 hours to 307 hours. This was probably because they used a relatively larger size of battery than conventional hearing aids. All BTE hearing aids investigated in the present study used a 675 zinc air battery, which is rarely used in modern, conventional BTE hearing aids except for high power BTE hearing aids. Therefore, the BTE style OTC hearing aids were larger in size when compared to modern conventional BTE hearing aids of similar gain.The mean volume range of the OTC hearing aids was 31.3 dB, indicating that there was about 31 dB flexibility in volume adjustment. However, the volume control (VC) was often not very effective as gain did not increase proportionally with volume control wheel adjustment. Half of the OTC hearing aids attained more than 50% of total gain at 1/4 volume setting. The VC characteristics could be divided into four types: (a) OTC A and F attained at least 75% of total gain at 1/4 volume setting; (b) OTC D, G, and J attained approximately 50% of total gain at 1/4 volume setting and the gain increased rapidly to at least 80% of total gain at 2/4 volume setting; (c) OTC E, H, and I attained less than 50% of total gain at 1/4 volume settings, but the gain increased rapidly to at least 70% of total gain at 2/4 volume setting; (d) OTC B and C attained approximately 50% of total gain at 2/4 volume setting. All OTC hearing aids reached nearly maximum gain at 3/4 volume settings. The percentages of total gain at different volume settings were plotted in Type d was the most effective VC and type a was the least effective among the four types of VC. OTC A had the poorest VC among all OTC hearing aids. Although OTC A (tone N) had a volume range of 30 dB between the 0/4 to 4/4 volume settings, there was only 6 dB difference between 1/4 and 4/4 volume settings. Consequently, it could be difficult for a hearing aid user to adjust the volume to an optimum listening level as rotation of the volume control will result in either too much or too little change in gain.In addition, hearing aids are not typically designed to operate at the full-on position in usual situations. Reserve gain should be allowed for hearing aid users, so that they have the freedom to adjust for different listening environments. Most prescription formulae suggest a reserve gain of 10 to 15 dB . It woulIn the simulated real-ear measurement, all of the OTC hearing aids could turn to full-on gain without feedback occurring. This was probably because the BTE hearing aids and ITE hearing aids were low-gain hearing aids with little output at high frequencies. Moreover, the long feedback pathway in the BW style may reduce the likelihood of feedback .In the present study, the performances of the OTC hearing aids were generally similar to those investigated by Cheng and McPherson  and the The appropriate hearing loss for each OTC hearing aid was estimated using the four prescription formulae and illustrated in Although the variety of appropriate hearing losses for OTC hearing aids was greater in present study than in that by Cheng and McPherson , it may There was a limitation in the estimation of hypothetical hearing loss in the present study since the prescription formulae included reserve gain of 10 to 15 dB and assumed the hearing aids were operated at mid volume settings . HoweverOTC A (tone L), F, and G were the only hearing aids that could meet the amplification needs of elderly people with presbycusis if a strict fitting outcome criterion was used. If a looser criterion of matching targets was used, OTC B also could be considered to match the amplification needs for presbycusis. Generally, BW styles could match the prescriptive targets at the high frequencies, but they provided too much low-frequency gain at the same time; thus they usually failed to match the targets at low frequencies; in contrast, BTE and ITE styles could match the fitting targets at low frequencies, but they usually failed to provide sufficient amplification in the high frequencies.Although OTC A (tone L), F, and G could fit a hypothetical presbycusis using the NAL-R formula, they provided 15 dB reserve gain only when they were operated at 0/4 to 1/4 VC settings. These three hearing aids had type a and type b VC characteristics, such that the gains increase abruptly between 0/4 and 1/4 VC settings. This attribute would make it difficult for wearers to adjust the gain to an appropriate level, especially for elderly people with poor manual dexterity. Overamplification or underamplification would be the likely result due to the poor VC range in these hearing aids . OTC B hThe present findings indicate that the electroacoustic characteristics of the selected, current generation OTC hearing aids are similar to those in previous studies over the past decades. There is no major improvement shown in the performance of OTC hearing aids over the years. All were linear hearing aids with less than optimal volume controls. Most of them showed unacceptable electroacoustic performance, such as sharp peaks in the high frequency region of frequency response, low HFA gain, poor amplification in high frequencies, and/or high EIN. However, THD levels, battery life, and feedback were generally not problematic in the OTC hearing aids.Reverse sloping hearing loss was still the most prevalent type of hearing loss that could be appropriately fit with the OTC hearing aids. This type of low-frequency emphasis hearing aid is not suitable for most people with presbycusis, who typically show high frequency sloping hearing loss. The prescriptive targets for presbycusis were generated using the NAL-R formula. Four of the hearing aid test conditions could match the prescriptive targets at four or more frequencies, and they were judged to meet the amplification needs of elderly people with presbycusis. However, their electroacoustic performance, such as ineffective volume control, high EIN, and irregular frequency response, may override their benefit in matching the amplification needs of clients with presbycusis. For example, the appropriate hearing loss derived from OTC A was a sloping hearing loss; thus OTC A was potentially suitable for elderly individuals with hearing loss associated with presbycusis. Nevertheless, OTC A had inadequate volume control parameters and attained approximately 80% of total gain at 1/4 volume setting, making it difficult for elderly wearers to adjust gain to an appropriate level.In summary, the low-cost OTC hearing aids investigated in the present study were not considered suitable for elderly people with presbycusis, who are likely to be the major users of OTC hearing aids. The inadequate performance of such OTC hearing aids may cause wearers to decline to adopt hearing aid use. Manufacturers should consider ways to improve VC effectiveness, lower EIN, and smooth the frequency response of OTC hearing aids. Moreover, they may consider increasing the gain at high frequencies and reducing the gain at low frequencies, in line with prescription formulae guidelines. Future OTC hearing aids then may be more suitable for their major client group—elderly people with presbycusis. On the other hand, most conventional hearing aids have advanced technology, such as directional microphones, noise-reduction algorithms, and automatic volume controls, which can improve the listening experience of wearers. In addition, the hearing aid prescribed by an audiological professional can appropriately fit the user because the electroacoustic parameters are specifically adjusted according to their individual hearing loss. Although conventional hearing aids are more expensive than OTC hearing aids, the benefits brought by conventional hearing aids may far outweigh their cost. To clarify this point further research should be done, using subjective rating procedures, on the fitting experience of current OTC hearing aid users . Qualita


Contrary to an apparent clinical consensus, duration of sound deprivation in one ear has limited value in predicting speech recognition outcomes of cochlear implantation in that ear. Outcomes of cochlear implantation are more closely related to the period of time for which the brain is deprived of auditory stimulation from both ears.In many countries, a single cochlear implant is offered as a treatment for a bilateral hearing loss. In cases where there is asymmetry in the amount of sound deprivation between the ears, there is a dilemma in choosing which ear should be implanted. In many clinics, the choice of ear has been guided by an assumption that the reorganisation of the auditory pathways caused by longer duration of deafness in one ear is associated with poorer implantation outcomes for that ear. This assumption, however, is mainly derived from studies of early childhood deafness. This study compared outcomes following implantation of the better or poorer ear in cases of long-term hearing asymmetries. Audiological records of 146 adults with bilateral hearing loss using a single hearing aid were reviewed. The unaided ear had 15 to 72 years of unaided severe to profound hearing loss before unilateral cochlear implantation. 98 received the implant in their long-term sound-deprived ear. A multiple regression analysis was conducted to assess the relative contribution of potential predictors to speech recognition performance after implantation. Duration of bilateral significant hearing loss and the presence of a prelingual hearing loss explained the majority of variance in speech recognition performance following cochlear implantation. For participants with postlingual hearing loss, similar outcomes were obtained by implanting either ear. With prelingual hearing loss, poorer outcomes were obtained when implanting the long-term sound-deprived ear, but the  Cochlear implants have been dubbed ''the most successful of all neural prostheses'' , helpingDuration of deafness is commonly identified as one of the main predictors of implantation success in adults, where higher performance in speech recognition is associated with shorter durations of deafness –5. The a“Optimization of the benefit from implants depend not only on the implant signal but also on its coupling to the central auditory system and other related brain systems to learn how to most efficiently obtain meaning from that signal”.Conversely, in adults, better hearing in one ear could contribute to higher outcomes of implantation in the other ear . This idIdentifying whether the impact of duration of sound deprivation on cochlear implantation outcome is ear, or brain specific has considerable clinical implications. In particular, cochlear implant clinicians must regularly decide which ear to implant first ,19–21. IThis paper examines the impact of long-term unilateral sound deprivation on outcomes of implantation in individuals who had large differences in the duration of sound deprivation for each ear prior to implantation. This is done by comparing speech recognition outcomes in adults with bilateral hearing loss using a single hearing aid and implanted in either the aided (better) or long-term unaided (poorer) ear. The contribution of potential predictors to outcomes of cochlear implantation is also examined.≥70dB) and unaided hearing loss in one ear for at least 15 years before unilateral cochlear implantation. Implantation was performed between 2000 and 2009. The surgery was conducted at one of the five following centres: the Québec Cochlear Implant Program (Canada), the Sydney Cochlear Implant Centre , the Melbourne Cochlear Implant Clinic , the Cochlear Implant Program at Linköping University Hospital (Sweden), and the Cochlear Implant Program at Karolinska University Hospital (Sweden). Participants were excluded from the study if there was evidence of surgical complication, device failure, or severe cognitive or psychiatric problems. A prelingual onset of hearing loss was defined as a severe degree of hearing loss before three years of age [Audiological data from adult participants (>18 years of age at implantation) with a bilateral hearing loss was included in this retrospective multicentre cohort study. All used only one hearing aid and had a severe  received the cochlear implant in the sound-deprived (poorer) ear. Demographics are presented in The duration of bilateral significant hearing loss as defined in Boisvert et al.  was usedEthical review, guidance and approvals to conduct the study were obtained from Macquarie University, New South Wales Department of Health, and Royal Victorian Eye and Ear Hospital Human Research Ethics Committees in Australia. Written clinical consent was obtained to collect and analyse the data anonymously.The relative contribution of potential predictors to outcomes of implantation was assessed with a multiple regression analysis using the SRS obtained with the cochlear implant alone as the dependent variable. In a general linear model, the ear implanted (better or poorer) and the presence of a prelingual hearing loss were included as fixed factors, while age, duration of sound deprivation in the implanted ear, and duration of bilateral significant hearing loss were included as covariates. The frequency of use of bimodal hearing (cochlear implant in one ear and hearing aid in the other) by participants in each group was also examined. A mixed model analysis of variance was conducted to compare SRS obtained in the two groups when tested with the cochlear implant alone and in the everyday listening condition . Comparisons were finally conducted separating participants with and without prelingual hearing loss.bilateral significant hearing loss and the presence of a prelingual hearing loss were found to explain the majority of variance in speech recognition scores following cochlear implantation  = 8.11, p<.001). Duration of sound deprivation in the implanted ear and placing the cochlear implant in the better or poorer ear did not significantly affect the outcomes.One argument often used to support implantation of the poorer ear is to increase patients’ probability of utilising bimodal hearing (i.e. using a hearing aid in one ear in combination with a cochlear implant in the other) . Three t = .54, p = .46). An interaction effect showed that the mean performance was improved for the group who received the cochlear implant in their poorer ear when tested in the everyday listening condition  compared to when tested with the cochlear implant alone  = 9.64, p = .002). For participants who received the cochlear implant in their better ear, performance was similar with the cochlear implant alone and in the everyday listening condition . This is because many of the participants who received the implant in their poorer ear used a hearing aid in the non-implanted ear in combination with the cochlear implant.A mixed model analysis of variance suggested no significant difference between the SRS obtained by participants implanted in their better ear  and participants implanted in their poorer ear  = 8.53, p<.001). A post-hoc Tukey HSD test showed that participants with postlingual hearing loss obtain similar outcomes with the implant in the better , or poorer ear . The outcomes obtained by participants with postlingual hearing loss were also similar to those of participants with prelingual hearing loss implanted in their better ear , but not in their poorer ear . A similar pattern of results was found when considering the everyday listening condition. This result demonstrates that sound deprivation affects outcomes of implantation differently in adults with prelingual and postlingual hearing loss. Based on the results obtained with the multiple regression analysis, we separated outcomes of participants with postlingual and prelingual hearing loss . An analThe data suggest that in adults with postlingual hearing loss, contrary to an apparent clinical consensus ,22, a loThe majority of individuals who received a cochlear implant in their poorer ear continued using a hearing aid in the opposite ear, enabling the additional benefits of hearing with two ears. In comparison, only a minor proportion of adults implanted in their better ear gained access to binaural hearing after implantation. Several studies have demonstrated consistent benefits of bimodal hearing over a single cochlear implant used alone –30, in ppresence of a long duration unilateral sound deprivation appears to negatively impact on implantation in a prelingually, but not a postlingually, deafened ear. This finding suggests that auditory deprivation in the first few years of life has a different effect to auditory deprivation after the acquisition of higher level auditory and language skills. This is consistent with studies that identify a critical period for the development of auditory skills and spoken language between birth and four years [The presence of a prelingual hearing loss in the implanted ear was identified as a main predictor of cochlear implantation outcomes. Consistent with previous studies Click here for additional data file.


One in ten people aged between 55 to 74 years have a significant hearing impairment in their better hearing ear (as defined by audiometric hearing thresholds). However, it is becoming increasingly clear that the challenges faced by older listeners cannot be explained by the audiogram alone. The ability for people with hearing loss to use cognition to support speech perception allows for compensation of the degraded auditory input. This in turn offers promise for new cognitive-based rehabilitative interventions. Working memory is known to be highly associated with language comprehension and recent evidence has shown significant generalization of learning from trained working memory tasks to improvements in sentence-repetition skills of children with severe to profound hearing loss. This evidence offers support for further investigation into the potential benefits of working memory training to improve speech perception abilities in other hearing impaired populations.This is a double-blind randomized active controlled trial aiming to assess whether a program of working memory training results in improvements in untrained measures of cognition, speech perception and self-reported hearing abilities in adult hearing aid users (aged 50 to 74 years) with mild-to-moderate hearing loss, compared with an active control group who receive a placebo version of the working memory training program.The present study aims to generate high-quality preliminary evidence for the efficacy of working memory training for adults with mild-to-moderate sensorineural hearing loss who are existing hearing aid users. This trial addresses a number of gaps in the published literature assessing training interventions for people with hearing loss, and in the general literature surrounding working memory training, such as the inclusion of an active control group, participant and tester blinding, and increased transparency in reporting.NCT01892007. Date of registration: 27 June 2013.ClinicalTrials.gov identifier:  More than one in ten people aged between 55 to 74 years have a significant hearing impairment (greater than 25 dB hearing loss (dB HL) averaged across 0.5 to 4 k Hz) in their better hearing ear . AlthougAuditory training has been used for many years as a rehabilitative intervention for people with hearing loss. It can be defined as a process that involves teaching the brain to listen through active engagement with sound. Auditory training has been shown to result in improved performance for the trained task, for example, frequency discrimination in normally hearing adults and children ,8. Howevet al. [et al. [auditory training for adults with hearing loss suggests a number of methodological and reporting inadequacies in published research, resulting in very-low to moderate quality evidence [Working memory has been defined in many ways. Engle and Kane  emphasizet al.  focus on [et al.  state th [et al. . Working [et al. ,18 and t [et al. . Working [et al. ,21. Diff [et al. ,23. It h [et al. ,25. Howeevidence . Thus, tet al. [Cogmed RM is a training software product for children or adults that aims to improve working memory, comprising verbal and visuospatial working memory and memory storage tasks. Brehmer et al.  demonstret al.  showed sThere are currently 10 million people in the UK with a significant hearing impairment , the majThe present study protocol presents novel independent research funded by the National Institute for Health Research (NIHR) and has been reported in accordance with the SPIRIT  2013 guidance for content of a clinical trial protocol .Does working memory training result in improvements in cognition, speech perception and self-reported hearing abilities in adults with mild-to-moderate hearing loss who are existing hearing aid users, compared with an active control group ?hypothesise that:We 1. Compared with the active control group, hearing aid users in the experimental group (adaptive working memory training) will have significant generalized improvements in untrained measures of cognition, speech perception and self-reported hearing abilities. Furthermore, these improvements will be significantly greater than for hearing aid users in the active control group who receive non-adaptive training.per se. The research edition of Cogmed RM working memory training will be used as this has been designed for double-blind randomized active controlled trials and provides no indication to either participants or testers of which training group  a participant has been allocated.The study is a single-center, phase II, double-blind, randomized, active controlled trial, with minimized allocation of participants to one of two groups Figure . One groOne initial assessment and two baseline sessions, conducted a maximum of 1 week apart (T1 and T2), will be completed prior to allocation of training. The two baseline sessions will help account for any improvements in outcomes as a result of test-retest effects  prior to the intervention, thus increasing our confidence in the estimation of subsequent intervention-specific effects.Working memory training will be delivered in participants’ homes via an online training portal. Participants will complete a total of 25 sessions (5 sessions per week for 5 weeks). Improvements for trained tasks will be assessed using the Cogmed ‘index of improvement’. Following training, participants will return for a post-intervention outcome assessment at T3. Participants in the active control group who receive the non-adaptive training will be unblinded following their T3 assessment and offered the adaptive training. Participants in the experimental group will remain blinded at T3 and will be invited to return for a 6-month follow-up assessment at T4 31 weeks) to assess retention of any post-training improvements in outcomes , and full ethical approval from Nottingham 2 NHS Research Ethics Committee (reference 08/H0408/172).Existing hearing aid users between the ages of 50 to 74 years with mild to moderate hearing loss, as defined by an audiometric air-conduction pure-tone averaged (averaged instead of average) (PTA) across octave frequencies between 0.25 to 4 kHz of 20 to 70 dB HL  in the b0.25-4k Hz 21 to 69 dB HL) sensorineural hearing loss  in the better hearing ear; and (4) internet access at home.Inclusion criteria are: (1) aged 50 to 74 years; (2) existing (3+ months) hearing aid(s) user; (3) mild to moderate (PTAExclusion criteria are: (1) having previously taken part in a training intervention study; (2) first language other than English ; (3) unable to use a desktop or laptop computer (as working memory training is delivered via the internet using a desktop or laptop computer); and (4) mild cognitive impairment as defined .Change in performance in an untrained measure of verbal working memory  will be the primary measure of efficacy in the present study. The Visual Letter Monitoring Task  is a visSecondary outcome measures assess multiple aspects of speech perception, cognition and communication abilities.The phoneme discrimination task assesses an individual’s ability to distinguish differences between phonemes presented on a continuum. Delivered using the Medical Research Council (MRC) Institute of Hearing Research System for Testing Auditory Responses (IHR-STAR) platform. Participants will be presented with three discrete phonemes from a continuum per trial and asked to identify the odd one out. Phoneme continua /a/ /e/ (easy) and /d/ /g/ (difficult) will be presented for a block of 35 trials in sequential blocks, with a 3-trial demonstration of continuum /a/ /e/ prior to the 2 blocks. The task will be adaptive based on participant performance using a three-phase adaptive staircase procedure (see  for furtHigh-predictability and low-predictability (context) sentences , based oThe Modified Coordinate Response Measure (MCRM) is a measure of speech perception ability in the presence of different maskers at an adaptive signal-to-noise ratio. The basic task is described by Hazan and colleagues , and is The digit span (backwards) subtest from the Wechsler Adult Intelligence Scale, Third Edition (WAIS-III)  is measuThe MRC Institute of Hearing Research Test of Attention in Listening (TAIL) is a measure of auditory attention  using toThe Test of Everyday Attention (TEA) subtests 6 (telephone search) and 7 (telephone search while counting) will be used to assess participants single  attention and dual  attention . In subtThe Size Comparison Span (SICSPAN) is a measure of working memory capacity including inhibition of semantic confusions . ParticiThe dual task is a measure of listening and memory designed to assess listening effort . ParticiThe Glasgow Hearing Aid Benefit Profile  is used The Hearing Handicap Inventory for the Elderly  is a selIn order to detect a minimum improvement of 1.5 words (15%) in the primary outcome measure  based on 80% power, a 1-sided type I error rate of 5%, using a pooled standard deviation of 2.118 to derive the effect sizes, a total of 27 participants are required in each training group. We anticipate a participant attrition rate of no more than 15%, and therefore will recruit a total of 31 participants per group.Participants will be sent a study information sheet at least 24 h before their first test session. At the first test session, participants will provide signed informed consent. All testing will be carried out at the NIHR Nottingham Hearing Biomedical Research Unit. Audiometric testing will be performed in double walled sound attenuating booth. Speech perception and cognitive testing will take place in a quiet, purpose-designed test room. Auditory stimuli will be presented in the free field via a single speaker  situated directly in front of the participant at their most comfortable loudness (MCL) level .Cogmed RM working memory training will be delivered via the internet at the participant’s home, using either their home PC or a laptop loaned by the NIHR Nottingham Hearing Biomedical Research Unit. Auditory elements will be presented in the free field using built-in or portable speakers at participants’ MCL. Training will be home-based with telephone monitoring once per week to ensure progress is maintained and to monitor for any practical or technical issues with training. Participants will be supported throughout their at-home training by a training aide, typically their spouse, who will offer support and guidance in accordance with Cogmed guidelines. Training aides will be instructed on their role by a qualified training coach at the NIHR Nottingham Hearing Biomedical Research Unit.Participants will be allocated either an ‘experimental’ or an ‘active control’ user ID to access the training URL by the chief investigator (HH) using Minim, a method of minimization . MinimizParticipants will be blind to group allocation and it will not be possible for participants to tell from the online training interface which group they have been assigned to.The researcher responsible for testing participants at baseline and post-intervention outcome assessments will not be involved in the allocation of participant IDs and will be blind to participants’ group allocation.Cogmed RM working memory training Figure  consistsFor the experimental group, training task difficulty (number of to-be-remembered items) is adaptive, based on individual performance, to maintain average daily performance levels of approximately 60% of trials correct.For the active control group, non-adaptive training tasks are fixed at a low-difficulty practice level (three to-be-remembered items) and task difficulty will not increase for the duration of the training.The chief investigator is the data custodian. This study will abide by the Caldicott principles. Data will be stored in accordance with NHS guidelines.Data collected on paper will be entered onto a database accessible only by the research team and stored alongside electronic data. The database will be password protected and held on the NIHR Nottingham Hearing Biomedical Research Unit network, which is also protected with a password that is changed every 12 months. Paper files will be stored in filing cabinets in a locked room. All identifiable files will be stored separately from data. Data will carry a unique (non-identifiable) study number. Electronic data is backed up daily, with backup files stored off site in a fireproof cabinet. Only the primary investigator, chief investigator, and the unit statistician will have access to the final data set.d, using the pooled standard deviation of the two groups.Analyses will be performed to include those of the 62 recruited participants who meet the study criteria and complete the trial. Any participant leaving the study before its completion will not be replaced. Missing data will be accounted for using a method of multiple imputation . Effect sizes will be calculated using Cohen’s Baseline characteristics  will be described for each group.The primary endpoint and first analysis of group data will take place at the end of the 7-week randomized controlled trial (week 7). Repeated measures analysis of variance (ANOVA) will be used to assess any main effects of time and training group  on the primary and secondary outcome measures. In addition, exploration of any significant interaction effects will enable the identification of whether Cogmed (adaptive) training for participants in the experimental group results in significantly different outcome performance than Cogmed (fixed) training for participants in the active control group. The mean difference in the primary outcome measure  for the main intervention assessment comparison (T2-T3) will be presented as a mean difference and 95% confidence interval (CI) for each of the two groups. Within-group and between-group comparisons for the primary and secondary outcome measures will be conducted using paired and independent t tests . Pearson’s product moment (or Spearman’s rho correlations) will be used to identify relationships between improvements in behavioral performance of speech perception and cognition and improvements in self-reported hearing ability, to help inform clinically significant benefits for people with hearing loss.The second endpoint and planned analysis will take place at the end of T4 (week 31), for the experimental group only, to examine the retention of any post-training improvements in the primary and secondary outcomes at a 6-month follow-up assessment. Repeated measures ANOVA will be used to assess any main effects of time the primary and secondary outcome measures for participants in the experimental group. The mean difference in the primary outcome measure  for the main retention assessment comparison (T3-T4) will be presented as a mean difference and 95% confidence interval (CI). Within-group comparisons for the primary and secondary outcome measures will be conducted using paired and independent t tests .Repeated measures ANOVA, paired t tests and independent t tests  will be performed where appropriate to assess intervention efficacy in subgroups of participants who are bilateral and unilateral hearing aid users, and those with high and low baseline working memory capacity. Analyses will identify whether there are any differences in pre-intervention to post-intervention outcome performance (week 7), and for the retention of any training-related improvements (week 31), across different participant subgroups.It is not anticipated that there will be any adverse events in this trial. However, should any adverse events be identified, these will be recorded and reported according to the trial sponsor’s  Standard Operating Procedures.Auditory training is currently used for the clinical management of people with hearing loss despite a lack of published high-quality evidence assessing its efficacy and mechanisms of benefit . BenefitThe present study aims to generate high-quality preliminary evidence for the efficacy of working memory training to improve cognition, speech perception and self-reported hearing abilities in adults with mild-to-moderate sensorineural hearing loss who are existing hearing aid users. This randomized active controlled trial addresses a number of gaps in the current published literature , offerinThe trial is currently in the recruitment phase. It is expected that recruitment into the study will be complete by 31 January 2014.dB: Decibel; GHABP: Glasgow hearing aid benefit profile; HHIE: Hearing handicap inventory for the elderly; HL: Hearing loss; MCRM: Modified coordinate response measure; MoCA: Montreal cognitive assessment; PTA: Pure tone average; SICSPAN: Size comparison span; STAR: MRC Institute of Hearing research System for Testing Auditory Responses; TAIL: Test of attention in Listening; TEA: Test of everyday attention.The authors declare they have no competing interests. Manuscripts reporting study results will be reviewed by Cogmed representatives 30 days prior to submission to a peer-reviewed journal. However, the NIHR Nottingham Hearing Biomedical Research Unit has the right to publish all statistical analyses regardless of positive or negative results.HH and MAF developed the protocol. HH drafted the manuscript. Both authors contributed to editing and approved the final manuscript. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR, or the Department of Health.


Untreated hearing loss can interfere with an individual’s cognitive abilities and intellectual function. Specifically, hearing loss has been shown to negatively impact working memory function, which is important for speech understanding, especially in difficult or noisy listening conditions. The purpose of the present study was to assess the effect of hearing aid use on auditory working memory function in middle-aged and young-older adults with mild to moderate sensorineural hearing loss. Participants completed two objective measures of auditory working memory in aided and unaided listening conditions. An aged matched control group followed the same experimental protocol except they were not fit with hearing aids. All participants’ aided scores on the auditory working memory tests were significantly improved while wearing hearing aids. Thus, hearing aids worn during the early stages of an age-related hearing loss can improve a person’s performance on auditory working memory tests. Age-related hearing loss in middle-aged (MA) and young-older (YO) adults is a public health problem in the U.S. affecting 20% of people between 45–59 years of age and 33% of people in their sixties . Age-relCurrently, hearing aids are the primary treatment for an age-related hearing loss. However, the uptake rates for adult hearing aid use are low; 20% for all hearing impaired adults, and 15% for adults with hearing loss in their fifties . Furtherdeprivation hypothesis, It has been suggested that a lack of auditory input from an untreated hearing loss could negatively affect the neural networks involved in certain cognitive abilities . That isFortunately, there is evidence that hearing aid use may improve older adults’ performance on auditorily presented cognitive tests because the amplified signal likely improves an individual’s perception of instructions and test items . Allen eIn the present study, we examined the effect of hearing aid use on auditory tests of working memory in MA and YO adults. Despite the interest in the association between hearing impairment and cognitive function, only a few studies have investigated whether use of amplification improves working memory performance . In addiBriefly, working memory is a system for the temporary storage, management, and manipulation of information required for carrying out complex cognitive tasks such as language comprehension . Models M = 68.7 years, SD = 4.1 years). All of the participants in the current study were part of a larger longitudinal hearing aid study. All participants had at least a mild sensorineural hearing loss, bilaterally , and no more than a 15 dB difference in hearing thresholds between ears at any audiometric frequency. This hearing loss criterion was selected so that the participants’ thresholds would be at least > 0.5 standard deviations from the normal hearing thresholds reported for these ages in the There were 24 participants divided among 11 MA adults 50–60 years of age , and 13 YO adults 63–74 years of age   adults, and a group of 8 YO (C-YO)  adults. The control participants were recruited in the same manner as the experimental participants in this study. If a participant did not meet the hearing threshold criteria for being fit with hearing aids, they were assigned to one of the control groups depending upon their age.None of the participants had worn or tried a hearing aid prior to participating in this study. All participants were native speakers of English and were paid an hourly wage for their participation. Institutional Review Board approval was obtained prior to commencement of this study in accordance with the Syracuse University IRB committee.Middle-aged and YO participants were fitted with ReSound Alera 9  receiver-in-the-canal hearing aids coupled to open dome ear molds, bilaterally. Hearing aid gain was determined based on the Desired Sensation Level (DSL v. 5) prescriptive method . DSL tarThe data-logging feature in the hearing aids was used to track the overall hours of hearing aid use over the 6 week hearing aid trial. The Practical Hearing Aid Skills Test Revised PHAST-R; , an eighn-back task  routed through a GSI-61 audiometer to a GSI loudspeaker  located 1 meter, at ear level, in front of the participant (0°azimuth). In the SSN condition, the background masker was played continuously throughout the task. Participants were required to repeat the entire R-SPIN sentence they heard during a 4 s interval that followed the presentation of each sentence, and to remember the final word in each sentence for later recall. The examiner recorded only the final key word in the sentence. The memory task was manipulated by varying the number of sentences in the set . After all the sentences in a given set were presented, the experimenter prompted the participant to recall as many of the previously reported final key words as they could, verbally, and in any order. Twenty-four sentences were presented in each of the six experimental conditions . Performance on the Reading Span test was computed based on the percent of correctly recalled final key words.n-back task . During Control-session 2, control participants were administered the Listening Span Test and the auditory N-back stimuli were 96% (SD = 2.7), 92% (SD = 4), 100% (SD = 0), and 98% (SD = 2) in quiet and 95% (SD = 1.4), 92% (SD = 3.3), 100% (SD = 0), and 96% (SD = 2.3) in background noise for the MA, YO, C-MA, and C-YO groups, respectively. Based on the 95% critical differences for speech recognition percentage scores, there were no significant differences in speech recognition scores among the four groups of participants in this study  scores were 98% (SD = 4), 95% (SD = 11), 100% (0), and 100% (SD = 0) in quiet and 98% (SD = 3), 94% (SD = 12), 100% (SD = 0), and 100% (SD = 0) in background noise for the MA, YO, C-MA and C-YO groups, respectively. Based on the 95% critical differences for speech recognition percentage scores, there were no significant differences in speech recognition scores among the four groups of participants in this study . Mean unis study .N-back digits were 96% (SD = 2.6), and 95% (SD = 1.5) in quiet and 96% (SD = 1.6), 96% (SD = 1.2) in background noise for the MA and YO groups, respectively. Based on the 95% critical differences for speech recognition percentage scores, there were no significant difference between aided and unaided recognition of R-Spin sentences and N-back digits for either group of listeners , and the YO participants used their hearing aids 11 h per day (SD = 6 h) based on hearing aid data log information. Aided speech recognition scores on the R-SPIN were 100% (SD = 0) in quiet and in background noise for the MA participants, and 100% (SD = 0) and 98% (SD = 1.3) in quiet and in background noise for the YO participants. Mean aided speech recognition scores for the isteners .post hoc comparisons were completed using the Bonferroni adjustment for multiple comparisons.Working memory function was assessed using the Listening Span test in quiet and in noise with and without hearing aids. Mean scores and standard errors of the mean on the Listening Span test in quiet and in noise, collapsed across context are shown in Figure F = 9.6; p = 0.001; partial eta-squared = 0.50]. Post hoc analysis indicated significant group differences for the 4 and 6 span conditions but, not for the 2-span condition. YO participants scored significantly lower on the Listening Span test  in the 4 span (p = 0.003) and 6 span (p = 0.001) conditions compared to the MA participants in both quiet and noise. There was also a significant two-way interaction between Listening Condition × Amplification . MA and YO participants scores on the Listening Span test were significantly (p < 0.001) higher  with amplification in the 4 and 6 span conditions but, only in the background noise listening condition. Interestingly, while their performance was improved with hearing aids, the YO participants’ aided scores on the Listening Span Test approximated the unaided scores of the MA participants in the noisy listening condition.There was a significant two-way interaction of Span × Group . Both groups of participants scored higher on the 2 span condition than the 4 and 6 span conditions (p < 0.001). All other main effects, two-way and three-way interactions were not significant (P > 0.05).Two age-matched control groups were used in this study to ensure significant changes in the experimental group were not a result of simply being re-tested on the Listening Span test over the 6 weeks. Mean Listening Span test scores for the MA and YO control participants in quiet and noise at their initial test session and at the second test session, which occurred 6 weeks later, are shown in Figure n-back across factors and participant groups, a 2 × 2 × 2 × 2 full factorial RMANOVA was performed on the factors back  listening condition , amplification , and group . There was a significant three-way interaction of amplification × back × group . Post hoc analysis indicated that the YO group scored significantly (p < 0.001) higher with hearing aids than without hearing aids in both the quiet and noisy listening conditions in the 1-back condition. However, there were no significant (p > 0.05) differences in 1-back scores for the MA participants in the quiet or background noise conditions with hearing aid use. Also, no significant (P > 0.05) differences were observed between aided and unaided performance in quiet and noise on the 2-back for either MA or YO participants.Participants’ mean unaided and aided scores on the auditory 1-back and 2-back in quiet and in background noise are displayed in Figure n-back over time for the MA and YO control groups, a 2 × 2 × 2 × 2 full factorial RMANOVA was performed on the factors listening condition , test session , and group . There were no significant (p > 0.05) main effects, two-way or three-way interactions.In Figure N-back test in quiet and noise pre-fit and post-fit (6 weeks) to determine whether there was a cognitive transfer after using hearing aids for 6 weeks. A RMANOVA was performed on the within subject factors session  and listening condition  and the between subject factor group . There was no significant interaction between session and group . Therefore, it appears that the effect of hearing aids on working memory is more perceptual in that the benefit from amplification was directly related to the improved transfer of the signal and not cognitive transfer because wearing the hearing aids for 6 weeks did not change unaided working memory.We also compared participants’ unaided auditory working memory performance on the n-back test in either of the two age-matched control groups who were not fitted with hearing aids. Thus, the significant changes in the experimental group were not a result of simply being re-tested over time.The purpose of this study was to assess the effect of hearing aids on auditory working memory function in MA and YO hearing impaired adults. The main finding of the current study was that MA and YO participants’ auditory working memory performance was significantly improved with hearing aid use. This finding is strengthened by the fact that we did not observe any significant changes in working memory performance on the Listening Span test or the auditory In this study, we specifically chose to measure the effects of hearing aids on working memory function because, numerous studies have reported on the importance of working memory ability for effective speech-communication in noise , and howaided scores on the reading span test approximated the unaided scores of the MA group. This suggests amplification may reduce the confounding effect of hearing loss on apparent early age-related decline in auditory working memory function.In the current study, both the MA and YO participants’ Listening Span test scores were significantly higher with hearing aid use. Although the YO participants working memory performance was improved with hearing aids, their performance never achieved the level to that of the MA group. Interestingly, the YO participants effortfulness hypothesis: the theory that the extra effort that a hearing-impaired listener must expend to successfully understand speech comes at the cost of cognitive processing resources that might otherwise be available for encoding the speech content in memory  than a cognitive transfer (long-term). Another way to measure this would have been to measure aided and unaided performance on the cognitive tests at weeks 1 and 6, and assess if the amount of hearing aid benefit increased over time. However, we did not obtain aided scores on week 1 because this was part of a larger longitudinal hearing aid study, which did not include aided testing at week 1. Regardless, results from the present study indicate that some type of frequency shaping/amplification should be used when testing auditory working memory in hearing-impaired adults, even with a mild degree of hearing loss, to reduce the potential negative effect a degraded peripheral representation of the signal could have on cognitive test scores.If the benefit from amplification on the 1-back test was more of a cognitive transfer effect, then the participants’ Using hearing aids in the early stages of age-related hearing loss, even when hearing loss is mild, can improve performance on auditory working memory tests in quiet and in background noise. The majority of MA and YO adults are still in the workforce, and although they may be able to “get by” without a hearing aid, it is important to consider the impact of their hearing loss on their working memory function. Although results from this study indicate wearing hearing aids can have a positive impact on working memory performance, future research should investigate if using hearing aids during the earlier stages of age-related hearing loss can reduce or even prevent some of the perceptual changes that result from auditory deprivation .The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Hearing aids are used to improve sound audibility for people with hearing loss, but the ability to make use of the amplified signal, especially in the presence of competing noise, can vary across people. Here we review how neuroscientists, clinicians, and engineers are using various types of physiological information to improve the design and use of hearing aids. Despite advances in hearing aid signal processing over the last few decades and careful verification using recommended clinical practices, successful use of amplification continues to vary widely. This is particularly true in background noise, where approximately 60% of hearing aid users are satisfied with their performance in noisy environments . DissatiMany factors can contribute to aided speech understanding in noisy environments, including device centered  and patient centered variables . Although many contributors to hearing aid outcomes are known , a large portion of the variance in outcomes remains unexplained. Even less is known about the influence interacting variables can have on performance. To help advance the field and spawn new scientific perspectives, Souza and Tremblay  put fortA typical example highlighting the interaction between upstream and downstream contributions to performance outcomes is that involving the cocktail party. The cocktail party effect is the phenomenon of a listener being able to attend to a particular stimulus while filtering out a variety of competing stimuli, similar to partygoer focusing on a single conversation in a noisy room , 6. The  input signal refers to the acoustic properties of the incoming signal and/or the context in which the signal is presented. It could consist of a single or multiple talkers; it could be an auditory announcement projected overhead from a loudspeaker at the airport, or it could be a teacher giving homework instructions to children in a classroom. It has long been known that the ability to understand speech can vary in different types of listening environments because the signal-to-noise ratio (SNR) can vary from −2 dB, when in the presence of background noise outside the home, to +9 dB SNR, a level found inside urban homes  or negative [✗] might seem straight forward, but decades of research on the topic of outcome measures show this is not the case. Research aimed at modeling and predicting hearing aid outcome  when the input signal is a single speaker in moderate noise conditions, provided they are paying attention to the speaker while using a hearing aid that makes use of a directional microphone. This same listener might struggle [✗] if this single speaker is a lecturer in the front of a large classroom who paces back and forth across the stage and intermittently speaks into a microphone. In this example, changes in the quality and direction of a single source of input may be enough to negatively affect a person's use of sound upstream because of a reduced neural capacity to follow sounds when they change in location and in space. This framework and these examples are overly simplistic, but they are used to emphasize the complexity and multiple interactions that contribute to overall performance variability. We also argue that it is overly simplistic for clinicians and scientists to assume that explanations of performance variability rest solely one stage/variable. For this reason, interdisciplinary research that considers the contribution of neuroscience as an important stage along the continuum is encouraged.A person's self-report or aided performance on an outcome measure can be attributed to many different variables illustrated in The experiments highlighted here serve as examples to show how far, and multidisciplinary, hearing aid research has come. Since the original publication of Souza and Tremblay , advance


AbstractMacrobrachiumrosenbergii, is a large shrimp extensively used in aquaculture whose grooming behaviors were analyzed in this study. Macrobrachiumrosenbergii exhibits three unique male morphotypes that differ in their behavior, morphology and physiology: small-clawed males (SM), orange-clawed males (OC) and blue-clawed males (BC). The largest and most dominant males, BC males, are predicted to have significantly different grooming behaviors compared to females and the other two male morphotypes. These BC males may be too large and bulky to efficiently groom and may dedicate more time to mating and agonistic interactions than grooming behaviors. Observations were conducted to look at the prevalence of grooming behaviors in the absence and presence of conspecifics and to determine if any differences in grooming behavior exist among the sexes and male morphotypes. Significant differences in the grooming behaviors of all individuals  were found. BC males tended to have the highest grooming time budget (percent of time spent grooming) while SM males had a relatively low grooming time budget. The grooming behaviors of the male morphotypes differed, indicating while these males play distinct, separate roles in the social hierarchy, they also have different grooming priorities. The conditions in which Macrobrachiumrosenbergii are cultured may result in increased body fouling, which may vary, depending on the grooming efficiencies and priorities of these male morphotypes. Overall, grooming behaviors were found to be a secondary behavior which only occurred when primary behaviors such as mating, feeding or fighting were not present.The giant freshwater prawn,  A behavioral hierarchy occurs among certain behaviors which are deemed essential to an organism. Ranking of behaviors by individuals is necessary when an organism is in conflict situations such as foraging , fightinThe environment that an organism inhabits is also an important factor in the behavioral decision making process. Organisms in resource-limiting environments or social situations  should prioritize those behaviors with the greatest resource profitability  before other subordinate behaviors . Thus, iGrooming is a behavior for removing fouling debris and organisms from body surfaces . It is aPageBreakAutogrooming in crustaceans is important for removing macro- and microscopic fouling organisms, debris, sedimentation, and algae from body surfaces . GroominGrooming behaviors have been studied for many crustacean groups, especially in decapod crustaceans such as penaeid and caridean shrimps , brachyuMacrobrachium has over 240 species (Macrobrachiumrosenbergii (Crustacea: Decapoda: Caridea), is a caridean shrimp native to rivers of Southeast Asia but has been introduced to most continents for aquaculture. Of the 1.2 million tons of globally cultured shrimps in 2000, only 10% was caridean shrimps. But of that 10%, almost 99.9% were the shrimp, Macrobrachiumrosenbergii  have similar grooming behaviors to other caridean shrimps; (2) BC males will have less time available for grooming than other males due to time dedicated to the protection of females, defense of territories and dominance behaviors; and (3) the grooming will be a secondary behavior as hypothesized by Macrobrachiumrosenbergii, especially the male morphotypes, a key understanding of the tradeoffs between body maintenance and social dominance may be elucidated. Grooming may be an important behavior at the lower levels of the social hierarchy  but not in the dominant tier  where mating and maintaining territories are essential. Understanding how fouling and grooming behaviors vary among morphotypes may impact yield and profit, therefore, aquaculture operators have expressed interest in the grooming behaviors of the morphotypes and the possible ramifications on the survivorship of the shrimps .Due to the importance of Macrobrachiumrosenbergii were transported overnight from Texas in April 2012 to the University of Tampa. Individual shrimps were added to labeled plastic holding containers (5.5-L), with pre-drilled holes that allowed water flow, and then placed in an 1816-liter fiberglass aquaculture tank with filtered, continuous flowing, aerated water. The individual containers reduced physical contact and agonistic interactions, ensuring that both shrimps’ appendages remained intact and death by cannibalism was eliminated. The containers allowed visual and pheromonal contact among individuals as water was able to flow through the pre-drilled holes. The three male morphotypes  were distinguished by morphological characteristics and correlations among mass and body measurements  in these solitary observations and placed into a 19-L (40 cm × 25 cm × 20 cm) aquarium with black backing and natural rocky substratum. The black backing ensured that the shrimp would not be influenced by either surrounding shrimps in other tanks or the observer. Water in the aquarium was continually filtered and frequently replaced with water from the aquaculture tanks. Shrimps were allowed to acclimate for 24-hr before testing and were not used if they had molted within seven days. Females with embryos (“eggs”) on their pleopods were not observed to control for the behavior among males and females. All grooming behaviors were recorded during the daylight cycle for 30-min using a digital recording device and then later transcribed to data sheets following the methods of Behavioral observations were conducted to study the grooming behaviors of The null hypothesis that all behaviors will be equally prioritized was tested. To observe how social interactions with conspecifics affect grooming behaviors, each male morphotype  and females were placed in a grooming situation where shrimps could physically touch through antennular and cheliped contact (but not fight) via holes in the individual containers. The objective was to compare grooming behaviors of individuals in an environment without visual or minor physical cues (Solitary Grooming – Observations #1) to that of an environment with visual and physical cues . These latter observations differed from the Solitary Grooming (Observations #1) because individuals in the isolated situation only had chemical contact through water with other shrimps but did not have visual or minor physical input that was present in the Social Grooming (Observations #2). Visual and minor physical contact with conspecifics was expected to reduce frequency and time allocated to grooming behaviors in these observations, since these behaviors have been predicted to be secondary. Shrimps  were observed in the aquaculture tanks in their individual containers for 15-min and their grooming behaviors were recorded. These shrimps were randomly selected from the first observations (Solitary Grooming) and observed 24-hr after being used in the first observations. The same process of recording behaviors was used as in the Solitary Grooming (Observations #1). The data collected in these social observations were extrapolated (multiplied by 2) in order to compare the data to those from the Solitary Grooming (Observations #1) (15-min × 2 = 30-min).PageBreakbehaviors of the male morphotypes  and females. The objective of these observations was to compare the frequency of grooming behaviors in an environment without visual cues  to that of an environment with physical contact . If grooming behavior is a secondary action incurring the same energy cost as primary behavior , grooming behaviors should be reduced in time and frequency during these observations compared to both the solitary and social observations . During these observations shrimps had physical contact with another individual in a test arena and their grooming behaviors were recorded along with all other behaviors such as swimming, antennular touching, mating, fighting and non-agonistic interactions (interactions with no aggressive behaviors). This is different from the Social Grooming (Observations #2) due to the increased level of interaction . In Observations #3, shrimps were paired based on morphotype and sex for a total of ten different treatments; there were two trials of each treatment for a total of N=20 observations  affect the priority of grooming PageBreakFour appendages were observed actively grooming the body: third maxilliped M3), first pereopod P1), second pereopod (P2), and fifth pereopod (P5)  were the M3 and P1, but there were no significant differences in the frequency of use among the grooming appendages among all three male morphotypes and females. The M3 and P1 were used equally among all groups    is the second pereopod (P2)  was 2,838 behaviors. Common grooming behaviors observed include M3 scraping the sensory structures (A1 and A2), P1 brushing the respiratory structures (enclosed gills) and general body grooming es) Fig. . As the es) Fig. . The thiP2) Fig. . The P2 P2) Fig. .Important sensory, locomotive, and morphological areas of the body were selected among the females and male morphotypes to determine if these areas were groomed equally. These areas and functionality include (1) the walking legs (P5–P8) (locomotive), (2) antennal scale (precision in agonistic interactions and steering and braking function) and (3) pleopods (reproduction and forward swimming). There were no significant differences in the grooming frequency of these selected areas for the females and all male morphotypes  . The part groomed for the longest average time was the gills Fig. , which w hrs. ThePageBreakPageBreakactivities for females and male morphotypes  between the BC males and all other groups  are not present.Overall in PageBreakPageBreakOf the females and male morphotypes, the BC males had the highest average time budget for grooming, 35.2%, which was significantly higher than that of females (10.2%) , not one grooming behavior occurred. Hence, the observations were ended prematurely at a lower sample size compared to the other observations (Observations #1 and #3). The shrimps were in a social situation where many behaviors such as searching for mates, displaying, touching and grooming can occur. The grooming time budget was 0% for all observations.PageBreakPageBreak2=104.5; P<0.001; Fig. The paired shrimps   ; prioritreopods) , 1979 anreopods) . Each dareopods) , 2004 haPageBreakMacrobrachiumrosenbergii and other carideans, the male morphotypes of Macrobrachiumrosenbergii differed in grooming behaviors. These morphotypes are known to differ in their behavior based on their niche in the social hierarchy, and therefore it is plausible their grooming behaviors and time dedicated to grooming may differ . The P2 appendage is also used in the protection and defense of females. The fact that the BC males dedicate much time to the grooming of this appendage indicates it is may be important in maintaining the dominance position of these males in the social hierarchy.PageBreaktaking precedence over grooming (Table We found that primary (higher priority) behaviors such as feeding and defense are of greater importance and should occur more frequently than grooming when primary behaviors are possible. Grooming was absent or rare when primary actions occurred , therefore grooming should be considered as a secondary behavior, as hypothesized by Macrobrachiumrosenbergii showed similar grooming behaviors and grooming time budgets compared to other caridean shrimps indicating grooming behaviors have evolved in response to the fouling pressures experienced in an aquatic environment. We found that the BC males dedicate much time to the care of the P2 appendages which are used in displays, protection and defense. This behavior contributes to the high time budget for grooming in the BC males. Grooming was also hypothesized to be a secondary behavior, only occurring when other behaviors are not essential (Macrobrachiumrosenbergii.As hypothesized, ssential . The resMacrobrachiumrosenbergii is frequently grown in aquaculture (aculture  with theaculture . Once thaculture . As a re


TCs are defined by very long (tens of micrometers) and slender prolongations named telopodes. At their level, dilations—called podoms (~300 nm), alternate with podomers (80–100 nm). TCs were identified in a myometrial interstitial cell culture based on morphological criteria and by CD34 and PDGF receptor alpha (PDGFRα) immunopositivity. However, the mechanism(s) of telopodes formation and/or elongation and ramification is not known. We report here the low-level laser stimulation (LLLS) using a 1,064-nm neodymium-doped yttrium aluminum garnet (Nd:YAG) laser (with an output power of 60 mW) of the telopodal lateral extension (TLE) growth in cell culture. LLLS of TCs determines a higher growth rate of TLE in pregnant myometrium primary cultures (10.3 ± 1.0 μm/min) compared to nonpregnant ones (6.6 ± 0.9 μm/min). Acute exposure (30 min) of TCs from pregnant myometrium to 1 μM mibefradil, a selective inhibitor of T-type calcium channels, determines a significant reduction in the LLLS TLE growth rate (5.7 ± 0.8 μm/min) compared to LLLS per se in same type of samples. Meanwhile, chronic exposure (24 h) completely abolishes the LLLS TLE growth in both nonpregnant and pregnant myometria. The initial direction of TLE growth was modified by LLLS, the angle of deviation being more accentuated in TCs from human pregnant myometrium than in TCs from nonpregnant myometrium. In conclusion, TCs from pregnant myometrium are more susceptible of reacting to LLLS than those from nonpregnant myometrium. Therefore, some implications are emerging for low-level laser therapy (LLLT) in uterine regenerative medicine.Telocytes (TCs) are a brand-new cell type frequently observed in the interstitial space of many organs (see  Thorough knowledge of the structure of the uterine wall is essential to contribute to the understanding of reproductive function. Alterations of normal function of human uterus are reported in pregnant and nonpregnant state. Often these disorders implicate the reproductive function and are difficult to manage in the absence of a specific treatment.www.telocytes.com) including the human uterus [Telocytes (TCs) were recently described as stromal/interstitial cells found in many organs  laser the telopodes for testing their ability to grow and the possibility of stimulation of telopodal lateral extension (TLE) growth. The ability of TCs to form homo- and heterocellular contacts with various cell types  in different organs –16 has aThe idea of optical stimulation and guidance was extensively tested on primary neuronal cell cultures or neuronal cell lines  of nonmenopausal women (mean age 42.5 years). Other five specimens were obtained from the uteri of pregnant primipara women , at the time of cesarean section. All patients received information about the study and signed an informed consent file. All experiments have been carried out in accordance with the EU guidelines and approved by the Bioethics Committee of “Carol Davila” University of Medicine Bucharest.Human myometrial samples were collected into sterile tubes containing Dulbecco’s modified Eagle medium (DMEM) supplemented with fetal bovine serum (FBS) 2 %, HEPES (1.5 mM), as well as 10,000 IU/ml penicillin, 0.2 mg/ml streptomycin, and 0.50 mg/ml amphotericin , placed on ice and transported to the cell culture laboratory. Samples were processed within 30 min from surgery. Cells were cultured using the procedure described in detail elsewhere .Immunofluorescent staining was performed on cells cultured on coverslips, at fourth passage. The cells were fixed in 2 % paraformaldehyde for 10 min, washed in phosphate-buffered saline (PBS), and then incubated in PBS containing 1 % bovine serum albumin (BSA) for another 10 min. Cells were washed again and permeabilized in PBS containing 0.075 % saponin for 10 min . Incubation with the primary antibodies was performed for 1 h, at room temperature, using antihuman antibodies: CD34, goat polyclonal (sc-7045), 1:50 , and PDGFRα rabbit polyclonal (sc-338), 1:100 . After three serial rinses, the bound primary antibodies were detected with secondary donkey anti-goat antibody conjugated to Alexa Fluor 546, 1:250, and goat anti-rabbit antibody conjugated to Alexa Fluor 488, 1:250; all were from Invitrogen Molecular Probes, Eugene, OR, USA. Nuclei were finally counterstained with 1 μg/ml 4′,6-diamidino-2-phenylindole (DAPI) (Sigma-Aldrich).Negative controls were obtained following the same protocol, but omitting the primary antibodies. Samples were examined under a Nikon TE300 microscope equipped with a Nikon DS-Qi1 camera, Nikon PlanApo ×20 and ×40 objectives, and the appropriate fluorescence filters.00, beam divergence <1 mrad, beam diameter 2.5 mm. The parameters of the laser beam  were controlled by the RoboSoftware 4.3 Pro SP2 . The beam was focused on the cells through a Plan-Neofluar ×100/1.3 oil objective. During telopodal stimulation, the laser output power was set to 60 mW, and the spot size was 2 μm. The laser spot size was controlled and done by optically de-focusing the beam to rich the desired size, similar to [The optical stimulation of the TLE growth was done by means of a MicroTweezers Module twinflex Rel. 4.2 system  mounted on an inverted microscope AxioObserver D1 . We used a diode-pumped solid-state IR neodymium-doped yttrium aluminum garnet (Nd:YAG) laser , continuous wave (cw) mode, wavelength 1,064 nm, power 3,000 mW, transverse mode TEMmilar to . The beaThe experiments of optical stimulation of TCs consist in exposing a viable telopode to a laser beam (as described above) by placing approximately half of the laser beam on a TLE. The laser beam position is continuously adjusted as the telopode expands laterally. The TLE growing speed has been calculated from the moment it started to grow after being stimulated with the laser to the moment it stopped growing and started to retract; considering the growing distance in a given time, the average growing speed was estimated.2 in air), and LLLS was performed in the next day. In both types of treatments, mibefradil is prepared into DMEM supplemented with FBS 10 %.TCs were continuously perfused using a MPS-2 multichannel perfusion system with a micromanifold of 100 μm  at a rate flow of 1 μl/s. In the acute experiment, LLLS is performed before (control) and after 30 min of mibefradil (1 μM)  continuous perfusion on two different telopodes of the same TC. TCs were chronically (24 h) exposed to mibefradil (1 μM) by overnight incubation at 37 °C in a humidified atmosphere . The values of growth rate are reported as mean ± SD. Unpaired Student’s In this study, we identified TCs in myometrial cell culture, using accepted criteria: morphology under phase contrast microscopy and immunocytochemistry criteria in fluorescence microscopy. TCs were seen as cells with very long telopodes in phase contrast microscopy Fig. . In fluoThe mean duration of TLE stimulation was around 30 min or above, and it was chosen depending on the moment TLE stopped growing or retraction. The period of TLE exposure to LLLS and the beam laser characteristics are comparable to the previous reports on in vitro neuronal stimulation , 18.Reactivity of telopodes to LLLS varies in pregnant and nonpregnant myometrium. There is a net difference between the reactivities to optical stimulation of telopodes originating from pregnant  in TCs from pregnant myometrium, which is significantly higher than 6.6 ± 0.9 μm/min (n = 5) in TCs from nonpregnant myometrium, p < 0.01, unpaired Student’s t test  and chronic (24 h) exposure to mibefradil was done, and the LLLS effect on TLE growth rate was measured. In pregnant myometrium, the LLLS effect was tested on TCs per se , that is significantly lower than that in control conditions . After chronic exposure to mibefradil, LLLS performed on TCs from pregnant myometrium indicated an inhibition of the growth process.The chronic exposure to mibefradil determined a decrease in the growth rate, 5.7 ± 0.8 μm/min  has an extensive medical use, and the idea of using sub-thermal doses of laser light dated from the early 1970s . AlThe differences in TC reactivity to LLLS highlighted by our study in human nonpregnant and pregnant myometrium are not surprising since previous morphological studies have proved significant differences in telopodal width and in podomic thickness and gauge in human nonpregnant and pregnant myometrium . A possiFrequency domain NIR spectroscopy has proved that optical properties of the human uterine cervix are influenced by the hormonal status depending on the phases of menstrual cycle  or by prIt was suggested that the TC network may be involved in mechanical modulations and remodeling in various organs . In partThe contribution of TCs in mechanical stretching during uterine contraction is still to be understood; nevertheless, membrane stiffness properties tested by LLLS can reveal interesting molecular mechanisms. It is of particular interest the fact that the telopodes of TCs from nonpregnant myometrium are intensively positive for vimentin , a cytosIn conclusion, taking into consideration the profound physiological myometrial remodeling during pregnancy, which involves extensive structural and molecular changes, our findings suggest that the molecular mechanisms activated in TCs by means of LLLS are distinct in human nonpregnant and pregnant myometrium. Therefore, LLLT in human uterus should consider these cellular differences in pregnant and nonpregnant myometrium, and the laser power and exposure time should be adequately chosen.


In open surgery procedures, after temporarily dimming the lights in the operation theatre, the Photo Dynamic Eye (PDE) fluorescence camera has, amongst others, been used for fluorescence-guided sentinel node (SN) biopsy procedures. To improve the clinical utility and logistics of fluorescence-guided surgery, we developed and evaluated a prototype modified PDE (m-PDE) fluorescence camera system.n = 16), oral cavity (n = 6), or penile (n = 5) cancer were included. The number and location of SNs were determined following an indocyanine green-99mTc-nanocolloid injection and preoperative imaging. Intraoperatively, fluorescence guidance was used to visualize the SNs. The m-PDE and conventional PDE were compared head-to-head in a phantom study, and in seven patients. In the remaining 20 patients, only the m-PDE was evaluated.The m-PDE works under ambient light conditions and includes a white light mode and a pseudo-green-colored fluorescence mode . Twenty-seven patients scheduled for SN biopsy for (head and neck) melanoma (−11 M (vs. 3.08 × 10−9 M) ICG in human serum albumin. In the head-to-head clinical comparison (n = 7), the m-PDE was also superior: (i) SN visualization: 100 versus 81.4 %; (ii) transcutaneous SN visualization: 40.7 versus 22.2 %; and (iii) lymphatic duct visualization: 7.4 versus 0 %. Findings were further underlined in the 20 additionally included patients.Phantom study: The m-PDE was superior over the conventional PDE, with a detection sensitivity of 1.20 × 10The m-PDE enhanced fluorescence imaging properties compared with its predecessor, and provides a next step towards routine integration of real-time fluorescence guidance in open surgery.The online version of this article (doi:10.1245/s10434-016-5186-3) contains supplementary material, which is available to authorized users. From each dilution 100 μL was pipetted in a black 96-well plate . The complete dilution range was then evaluated to determine the detection sensitivity of the m-PDE and c-PDE fluorescence camera systems. Hereby, the head of the fluorescence cameras was fixed, perpendicular, at a 14 cm distance from the well-plate surface. This allowed capture of the whole dilution range in the field of view.A 5.0 mg/mL (6.45 × 10Imaging of the plate was performed under different settings—white light (m-PDE only) and fluorescence (both systems) and under various light conditions: (i) all lights in the operating room turned on ; (ii) satellite lamps directly lighting the sterile field turned off, but the plenum and surrounding lights on (referred to as ‘ambient light’ conditions); and (iii) all lights in the operating room dimmed. For the m-PDE fluorescence camera system evaluation, in all experiments the pseudo-colored green setting was used.As a reference for the fluorescence intensity measured with the c-PDE and m-PDE fluorescence camera systems, the ICG-based dilution range was also measured on preclinical, cooled, black box, camera systems . The fluorescence image obtained with the IVIS Spectrum was presented in a pseudo-colored glow scale, whereas for the Pearl Impulse, the fluorescence signal was presented in a pseudo-colored green scale. For both systems, the fluorescence images were overlaid onto a black and white background image.For quantification of the fluorescence signal measured with the IVIS Spectrum, in the acquired fluorescence image, regions of interest were drawn surrounding the wells after which Living Image 3D analysis software  was used to quantify the signal intensity per well.Light spectra of the different lamps present in the operating room were determined using a Jobin Yvon VS140 linear array fiber spectrometer  in the 300–1200 nm range, with an integration time of 0.1 ms. The fiber was held at a 2-meter distance from the lamp from which the light spectra were measured.The absorption and emission spectrum of ICG-HSA (concentration: 1.5 × 10–9 M) was measured using an Ultrospec 3000 UV/Vis spectrophotometer  and an LS55 fluorescence spectrometer . Solutions were prepared in a 3 mL quartz cuvet .n = 6) or penis (n = 5), head and neck melanoma (n = 11), or melanoma on the trunk or on an extremity (n = 5) scheduled for sentinel node (SN) biopsy with subsequent treatment of the primary tumor/re-excision of the melanoma scar were prospectively enrolled after obtaining written informed consent. All included patients were clinically node-negative as defined by palpation and ultrasound-guided fine needle aspiration cytology. Patient characteristics are shown in Table Patients with squamous cell carcinoma of the oral cavity pathological specimen analysis for oral cavity cancer,Preparation and administration of the hybrid tracer ICG– In patients with head and neck malignancies, primary tumor removal or re-excision of the melanoma scar was completed prior to performing SN biopsy. In penile cancer patients and patients with a melanoma on the trunk or on an extremity, SN biopsy was performed prior to treatment of the primary tumor site or the melanoma scar. A schematic overview of the intraoperative SN excision procedure is given in Fig. −11 M ICG–HSA) could be easily detected using this system   and melanoma (n = 3)), a total of 27 SNs were harvested  . For the c-PDE, with all lights in the operating room dimmed an overall detection rate of 81.4 % was found. The m-PDE system visualized 40.7 % of the SNs transcutaneously , while the c-PDE system visualized only 22.2 % . In two patients, a lymphatic duct leading to an SN was visualized with the m-PDE (ambient light conditions), whereas no lymphatic ducts could be visualized with the c-PDE (dimmed light conditions). Further detailed results can be found in Table Electronic supplementary Fig. SI1 presents the surgical workflow for the c-PDE  and m-PDE  fluorescence camera system. When using the c-PDE , lights in the operating room had to be dimmed in order to visualize the SNs. This temporarily stalled the surgical procedure. Forceps were often placed at the location of the SN, after which the lights in the operating room were turned back on to visually confirm the localization of the SN. This was followed by SN excision and fluorescence imaging to confirm removal of the SN. This process was repeated for each individual SN. When working with the m-PDE , the presence of ambient light, presentation of the pseudo-colored green fluorescence images on a gray-scaled anatomical background, and the ability to switch the m-PDE to white light mode, combined, allowed the surgeon to directly verify the anatomical location of the SNs and proceed with their excision in a sequential manner. Here, the white light mode allowed us to optimally focus the camera. Please see Fig. n = 2), penile cancer (n = 5), and (head and neck) melanoma (n = 13). From these patients, 73 SNs were harvested , of which 35.6 %  could be visualized transcutaneously , allowed superior optical SN visualization compared to blue dye in, for example, patients with vulvar or penile cancer,In the current study, we evaluated the effect that technical improvements have on the performance of the fluorescence camera. For this, the ‘new’ prototype m-PDE fluorescence camera was evaluated in relation to the ‘old’ c-PDE. After evaluation in a phantom set-up, its value was defined in patients who were to undergo an SN biopsy procedure for (head and neck) melanoma, oral cavity, or urological malignancies using the hybrid tracer ICG–The increased sensitivity of the m-PDE compared with the c-PDE, as concluded from the phantom studies, translated nicely in an improved clinical utility of the m-PDE. In a comparative series of seven patients, the reported two-to-three orders of magnitude increase in detection sensitivity resulted in a 14.8 % increase in SN visualization. The value of the m-PDE fluorescence camera system was further underlined in 20 additional patients. With the m-PDE, 35.6 % of the SNs could be visualized transcutaneously and, for 45.2 % of the SNs, lymphatic ducts were visualized. Its utility was further enhanced by (1) the fact that the fluorescence image of the m-PDE is corrected real-time for the influence of ambient light, meaning that the lights in the operating theatre did not have to be dimmed when performing fluorescence imaging; (2) the ability of the m-PDE to show the pseudo-colored green fluorescence image on a gray-scale anatomical background image; and (3) its ability to directly switch between the fluorescence light and white light mode. Given the clear clinical potential of this approach for ICG, which is not a particularly bright dye with a relatively short luminescence lifetime, this concept may, in the future, be successfully expanded to other luminescent tracers that have found their way into the clinic.10The technological evolutions realized in the m-PDE help minimize the disturbance of the clinical workflow and help to transform fluorescence imaging from a confirmatory modality to one that provides real-time ‘on-screen’ guidance during SN excision Below is the link to the electronic supplementary material.