A good audiologic diagnosis is increasingly more important in the practice of audiology, in order to understand patients’ needs for selection and fitting of hearing aid devices.Show recent literature that mention the concept of cochlear dead regions, diagnostic strategies and its relevance in the process of selection and fitting of hearing aids.to carry out a bibliographical survey on dead cochlear regions. Dead cochlear regions were described as regions where inner hair cells and/or adjacent neurons do not work. Therefore, in these regions, the information generated by basilar membrane vibration is not transmitted to the central nervous system. However, a tone at a frequency correspondent to that of dead regions, provided it being sufficiently intense, can be perceived in regions near this zone where inner hair cells and/or nervous fibers still work.The identification of dead regions in the cochlea is used to obtain better results in the process of selection and fitting of hearing aids because the pieces of information generated by inner hair cells to the auditory nerve are important to better identify sounds, mainly those related to speech. It is extremely important for the professional who works with audiology to have theoretical and practical knowledge in order to carry out a proper audiological diagnosis. It is based on the knowledge of how much and how the patient hears that one may think of the patient’s need for hearing aids.Increasingly today, patients with hearing impairment are looking for auditory rehabilitation, and a great part of its success is related to the quality of auditory diagnosis, because hearing aid calibration is directly related to the information acquired in the exam.Individuals with sensorineural hearing loss may present different types of cochlear failures, and there may be lesions in the outer hair cells (OHC) and/or inner hair cells (IHC), and the type of lesion impacts the individual’s response when they hear sound stimuli.Moore et al. (1999a)According to Zemlin (2002)Thinking about the differences in the results found in hearing aid fitting in individuals with sensorineural hearing loss, however with different audiometric configuration (flat or in slope) is that Moore and Glasberg (1997)Moore (2001a)Cochlear dead zones can not be diagnosed based on the audiogram. Thus, Moore (2000)Identifying cochlear dead zones has helped in selecting and fitting hearing aids, because the information generated by the IHC to the auditory nerve is important for a better sound recognition, especially speech sounds.With these cochlear dead zones, the device’s amplification region shall be prescribed with caution, so that the patient may have the best possible hearing aid performance in relation to speech recognition, since the IHC are inactive.Considering that studies on the cochlear dead zone have only recently started, and that this diagnosis is yet to be inserted in the clinical routine of audiology, the goal of the present investigation is to discuss recently published literature involving concepts of cochlear dead zones, diagnostic strategies and its importance in the selection and fitting of hearing aids.According to Moore and Glasberg (1997)Moore (2004)Moore et al.(2000)Another group for study was formed by individuals with hearing loss of varied audiometric configurations. Of the 20 ears assessed, we identified 14 ears with dead zones in their cochleas. The cochlear dead zones were identified when the masked thresholds were at least 10 dB above absolute thresholds and 10dB above TEN ERB masking level. These results were confirmed through the Psychophysical Measure test of tuning curves. Presenting a signal at a given frequency, the curve peak was shifted from the dead zone to a neighboring functional area in the cochlea. The TEN test was considered by the authors as a simple and effective method to detect and outline cochlear dead zones. However, they stress that some aspects have to be considered in order to confirm the presence of dead zones in the cochlea, since most of the individuals in the study presented acquired hearing loss, commonly associated with hair cell lesions, and this did not happen in congenital hearing loss, therefore, interpreting the findings must be carried out separately for each case.Moore (2004)According to Moore and Alcántara (2001)Different cochlear disorders have relations with changes in the tuning curve shape. When the inner hair cells are damaged, the neuronal fibers corresponding to this region present high thresholds both at the tip and at the curve end, however its configuration is not altered. When the damage happens only to the outer hair cells, the fibers that innervate this region present considerable sensitivity loss at its ends. The result of these changes is a broad “U”-shaped tuning curve, without a defined tip. In other cases, different levels of involvement may affect both the outer and inner hair cells, resulting in sensitivity and tuning losses.The same authors describe the psychophysical test of tuning curves, used to identify dead cochlear zones. The methodology suggests the presentation of a sine signal of fixed frequency and at the level of 8 to 22 dB NS, with concurrent masking on the same side. The noise used was of narrow band, with variable center frequency and with masking band of 80Hz. The tuning curve was obtained by determining the necessary masking level to mask the sine signal for 12 varied frequencies, and the tuning frequency was identified as the frequency (point) obtained with the lowest masking level (more effective masking level). In normal hearing individuals, the tuning curve presented its peak at the tuning frequency equivalent to the frequency of sine signal presented, however, it was obtained using higher masking levels than the ones used for normal hearing people In order to diagnose cochlear dead zones, some researchers proposed the possibility of using other wide band noises, different from TEN.Eguti (2002)In the sample of 10 individuals with normal hearing, there was a 5 dB HL variation over the absolute hearing threshold with the white noise, however, it was not considered as a positive result for the possible presence of dead zones in the cochlea, although Moore et al. (2000)White noise has masking effectiveness in the frequency range between 750 and 6000 Hz, and less efficacy in the lowest and highest frequencies, that is, 250, 500 and 8000 Hz. According to Sanders and Hall III (2001)The importance of diagnosing cochlear dead zones in the hearing rehabilitation processStelmachowicz (2001)Baer, Moore and Kluk (2002)Vestergaard (2003)13 applied the TEN test and assessed speech recognition of a filtered speech in 22 individuals with moderate to profound sensorineural hearing loss, users of hearing aids, used to a substantial amount of sound amplification. The author’s goal was to check the TEN test feasibility and its capacity to reveal functional impairments. When the masking level was very close to the absolute threshold, many individuals had difficulties hearing because of noise. Nonetheless, this fact did not compromise the TEN test feasibility. Eleven individuals presented the possibility of having dead zones in their cochleas. The recognition of monosyllable words was carried out under four filtering conditions chosen individually with low-pass filters and another broad band condition, presented at 65 dB SPL, by means of a speaker, with individuals using their hearing aids. Individuals with cochlear dead zones presented a better performance than individuals without it for hard to hear speech, especially when hearing reduction happened because of the removal of high frequency tips. Patients with cochlear dead zones are used to perceiving filtered speech because their hearing works as a low pass filter. Individuals without these dead zones are more affected by removing the high frequencies from the hearing information. In some cases, there was no consistent information between the benefit of filtered speech and the spectral location of the dead zone. Other studies would be necessary in order to explain the results in a satisfactory way.Gordo (2004)Almeida and Buzo (2005)15 investigated the presence of cochlear dead zones in a patient with sensorineural hearing loss and difficulty to accept bilateral amplification. They obtained absolute thresholds for air conduction for each ear in the frequencies of 250, 500, 1000, 1500, 2000, 3000, 4000, 5000, 6000, 8000 and 10000Hz first without and then in the presence of ipsilateral noise to the signal in the intensities of 30, 50 and 70 dB ERB. In the right ear, in which the patient has been using a hearing aid for 6 years now, absolute thresholds obtained with and without masking were similar. Now, for the left ear, the thresholds obtained in the presence of noise in the frequencies between 3000 and 10000 were higher, and this speaks for the presence of dead zones in this range of frequencies. The authors considered that the TEN test was an effective and simple procedure used to determine and outline the presence of dead zones in the left ear, matching patients’ complaints of the difficulties in accepting left ear amplification.We believe that, with the progress in diagnostic techniques in the area of clinical audiology, there came the possibility of better understanding the hearing of patients who are eligible to use hearing aids.Thus, studies favoring cochlear dead zones diagnoses started having a growing importance for those who study and/or work with audiological diagnosis, as well as the selection and fitting of hearing aids.Based on this concept of cochlear dead zones described by Moore and Glasberg (1997)Moore’s study (2001a)In order to check for the existence of dead zones in the cochlea, Moore et al. (2000)In the studies carried out by Baer, Moore and Kluk (2002)11, Vestergaard (2003)Another diagnostic means is the psychophysical measure of tuning curves, described by Moore and Alcántara (2001)Eguti (2002)We believe studies aimed at diagnosing cochlear dead zones must continue; and it is important that professionals involved in hearing rehabilitation include this assessment among routine audiological tests, when necessary.Audiograms provide important information so as to consider the presence of cochlear dead zones, however, this diagnosis may be carried out only after performing proper tests.We also believe that the results from a patient eligible to use hearing aids depend, among other things, of our own knowledge regarding sound amplification necessary for each individual in particular, and the investigation of the presence or not of cochlear dead zones is one more information that may contribute to the success of hearing rehabilitation.


Aim: To compare air and bone Auditory Brainstem Response results in children under 2 months of age with normal hearing. Study design: clinical with transversal cohort. Materials and Methods: 12 children who passed the hearing screening were evaluated using air and bone Auditory Brainstem Response. No contralateral masking was used in the bone conduction test. The responses were compared and analyzed by the McNemar test and repetitive measurements of the variance test. Results: There were no statistic differences between air and bone conduction Auditory Brainstem Response thresholds (p>0.05). The bone conduction latency for wave V was statistically higher than air conduction latency (p=0.000). Conclusion: There was agreement on the results recorded for air and bone conduction Auditory Brainstem Response for threshold intensities; latency for bone conduction wave V was statistically higher than the air conduction latency.The differential diagnosis of hearing loss with air and bone Auditory Brainstem Response in small children has not been enough studied in Brazil. The auditory system wholeness is extremely important for human development, since hearing is the way to acquire language and speech - means through which the child organizes and understands the universe, transmits feelings, understand others, interacts with the environment and acquires knowledge.So much so that the hearing impaired may have difficulties in language development, both oral and written, in cognition and socio-emotional. In order to be possible to overcome them, enhancing communication and learning capacity. The Joint Committee on Infant Hearing (JCIH)In the United States, a study carried out in Rhode Island found a prevalence of 3.24 children with severe to profound sensorineural hearing impairment (HI) for every 1000 births.3 As for air conduction impairment, the same study showed a prevalence of 20:1000.Having seen such figures, the JCIH2 recommends that the UNHS be carried out at the newborn discharge from the hospital or in the first month of life. In cases when the screening finds a fault, the baby should be referred to an otorhinolaryngologist and a speech and hearing therapist in order to conclude the diagnosis up to the third month of life, so that therapeutic intervention may happen before the 6th month of age.In order to confirm the diagnosis of HI, a battery of objective tests, such as acoustic immitance, transient stimulus (TSOAE) and distortion product (DPOAE) otoacoustic emissions (OAE), Brainstem Auditory Evoked Potential (BAEP), and auditory behavior that in children below 6 months of age may not correspond precisely to the toddler's hearing acuity.The BAEP is a test that assesses the neural synchrony from an external sound stimulus, generating a complex response that represents the activity of some anatomical structures. Together with other tests, it allows us to estimate hearing, since it evaluates the auditory nerve integrity  all the way to the brainstem.Thus, BAEP's recording may be influenced when there is some sound conduction impairment , or some change in neural conduction (e.g. some auditory neuropathy or a tumor).The BAEP's triggering stimulus, usually a click, may be given by the air conduction (AC), which is usually carried out, or by bone conduction (BC), by means of a bone vibrator placed on the postero-superior auricular portion at 45° from the external acoustic meatus orifice.In those cases in which the AC BAEP is altered in newborns, it is recommended to do a BC BAEPNonetheless, there are very few research papers using BC BAEP, and the literature shows much protocol disputes, making it difficult to classify a result as normal, its comparison with AC results and, consequently, the clinical applicability of this method. Thus, the goal of the present investigation was to compare AC and BC BAEP responses in children up to 2 months of age without hearing loss.This investigation was carried out in the department of electrophysiology of our institution, from March to April of 2004. The project was approved by the Ethics Committee of our University, under protocol # 0142/2003 and by its Research Committee.We evaluated twelve children with mean age of 20 days (standard deviation of 7.89 days) from the neonatal hearing screening service, whose parents accepted participating in this study and signed an informed consent form.•no complaints regarding the children's hearing;•no pre, peri and/or post-natal complications, or risk factors for hearing impairment according to the JCIH2;•type “A” tympanometry, with a compliance peak around 0daPa, of which variation would not exceed −100 daPa (GSI 33 immitancemeter with a 226 Hz probe);•presence of transient stimulus otoacoustic emissions (TSOAE), with general reproducibility•attention reaction to sound and cochleo-eyelid reflex for the reco-reco and agogô instruments, respectively;•presence of waves I, III and V, with absolute interpeak and latency times within normal ranges for the age during BAEP exam at 80 dBHL (Smart EP - Intelligent Hearing Systems);Inclusion criteria were:The children who did not have the aforementioned criteria were referred to otorhinolaryngological and speech and hearing assessment.We recorded BAEPs waves by AC and BC using the version 2.1X. Smart EP - Intelligent Hearing Systems device, with the children under natural sleep, and usually after a meal.The reference leads were deployed on the right (A2) and (A1) mastoid bones, and the live (Fz) and ground (Fpz) electrodes were placed on the forehead, after proper skin cleaning and the impedance between electrodes was considered less than 5000 ohms.o insertion phones, with proper fitting for newborns. We survey waves I, III and V in the intensities of 80 dBHL, 60 dBHL, 40 dBHL and 30 dBHL.In order to record BAEPs waves by AC we used EARTONE 3For BC BAEP recording we used a Radioear B-71 bone vibrator deployed on the postero-superior ear portion, fixing it with a 1582 model, 5cm wide, autoadherent 3M Coban elastic band, with power of 400 ± 25g, measured by a model 8264-M scaled Ohaus - Spring Scale. Wave V was investigated in the intensities of 40dBHL and 30 dBHL. The test was carried out without contralateral masking.The parameters used for BAEPs recordings are depicted on In order to compare the results attained by Ac and BC, we used:1-presence or absence of wave V by BC in the intensities of 40 and 30 dBHL with or without wave V by AC in the right and left ear of each participant  on the following way:40 dBHL: wave V VO x wave V VA RE40dBHL: wave V VO x wave V VA LE30 dBHL: wave V VO x wave V VA RE30 dBHL: wave V VO x wave V VA LE2-BC wave V latencies mean values with AC wave V latency mean values on both, the right and the left ears in the intensities of 40 and 30 dBHL.The first association was tested by the McNemar test and the second by the variance analysis with repetitive measures, according to aforedescribed methods.At 40 dBHL all the assessed children (100%) responded both by air and bone conduction; and 11 children 92%) responded by air and bone conduction on the right side. At 30 dBHL 75% and 58% of the children presented response both for the AC and BC on the right and left ears, respectively. , 2 and 3% respondAs to AC wave V latency time, at 40 dBHL, we recorded a mean time of 7.39ms, with a minimum of 6.35ms and a maximum of 8.6ms. And, at 30 dBHL, by AC, we recorded a mean time of 7.94ms, with a minimum of 6.75ms and maximum of 9.7ms.As to BC, at 40 dBHL, we recorded a mean time of 9.18ms, with a minimum of 8.45ms and maximum of 9.55ms. And, at 30 dBHL, by BC, we recorded a mean time of 9.72ms; 9.05ms the minimum and 10.7ms the maximum time recorded.BC BAEP, although it is recorded and interpreted as its AC counterpart, does bear some peculiarities. In executing this protocol, we had some difficulties that should be stated for future investigations.The bone vibrator emits electromagnetic energy, that interferes in the recording, causing artfacts.These electromagnetic artifacts make it difficult to visualize waves I and III, and because of it, we chose to study only the wave V. Moreover, the maximum intensity emitted by the bone vibrator is of, approximately, 50 dBHL, and this generates a small response amplitudeBoth the position and the power of the bone vibrator are able to alter wave V latency time.There is also the issue of masking the contralateral ear. The click interaural attenuation by bone conduction in children below 1 year is of approximately, 25 to 35 dBHL, needed mainly for stronger intensities, of masking the non-tested ear.In this first study, because of the children's ages, the presence of otoacoustic emissions during hearing screening (inclusion criteria) and, still, because at the time we had no practical experience with BC BAEP, we chose not to use contralateral masking. Notwithstanding, we believe in the need and relevance of BC BAEP with contralateral masking for later clinical application, since there may be unilateral hearing loss with screening failure on this side and masking is the only option we have in order to isolate the ears and have reliable results for the right and left ear separately.Comparing the presence of waves V obtained by AC and BC in the intensities near the auditory threshold, we did not obtain statistically significant differences, indicating that there is a response agreement for BAEPs captured by both pathways in normal children, and further suggesting that a difference between both traces indicates conductive hearing loss. Moreover, analyzing results from These data corroborate those from other investigationsAs to wave V latency time, comparing the mean values from the recording obtained by air conduction with bone conduction wave V recordings in the intensities of 40 and 30 dBHL, we obtained latency values statistically higher in BC when compared to AC (p=0.000), , regardl18As to the click stimulus frequency range by AC and BC, some authorsNow, as to the bone vibrator power and positioning, studies15 show that the weaker the bone vibrator placement, the larger will be the latency time. In the present investigation, we used a strength of 400 ± 25g and, thus, for future comparisons we should use the same protocol. We know that, if we increase the power with which the bone vibrator is tied to the skull, we reduce the latency time recorded.15 The authors have shown that, when they used powers of 425g, 325g or 225g, the BC latency time was higher than that of AC. However, when they used a power of 525g the opposite happened, in other words, the AC latency time was greater.15 The authors suggest using a power of 425 or 525g since lower power reflects less effectiveness in cochlear stimulation, and there is also the possibility that the bone vibrator may shift with the child's movements. In the present investigation, we kept constant both, the bone vibrator power and positioning, keeping it with elastic bands, and we did not have accidental shifting and alterations in the findings.Some authors we consulted1)There are no statistically significant differences as to the presence of wave V by AC and BC in the intensities close to the auditory threshold.2)Wave V latency registered by BC is statistically higher than the latency recorded by AC.By comparing the BAEP's responses by AC and BC in children up to 2 months of age without hearing loss, we may conclude that:


Beauveria bassiana  produce a plethora of toxic secondary metabolites that either facilitate fungal invasion or act as immunosuppressive compounds. These toxins have different chemical natures, such as nonribosomal peptides and polyketides. Even though their precise role is poorly understood, they are usually linked to virulence. These fungal secondary metabolites are produced by the expression of gene clusters encoding the various proteins needed for their biosynthesis. Each cluster includes synthetases for nonribosomal peptides (NRPS), polyketides (PKS), or hybrid NRPS–PKS genes. The aim of this review is to summarize the information available from transcriptomics and quantitative PCR studies related to the expression of B. bassiana NRPS and PKS genes inside different insects as the infection progresses; as for the host immune response, to help understand the mechanisms that these toxins trigger as virulence factors, antimicrobials, or immunosuppressives within the context of a fungus–insect interaction.Entomopathogenic fungi are extensively used for the control of insect pests worldwide. Among them,  Beauveria bassiana  is a generalist (broad-spectrum host range) insect pathogen able to infect nearly 1000 insect species [B. bassiana is the penetration of the insect cuticle, which represents the first encounter and barrier between the fungus and host [B. bassiana deploys a combination of biochemical and mechanical tools to make its way through the insect integument into the hemocoel [Metarhizium spp. mainly produce destruxins (cyclic hexadepsipeptides), and Beauveria spp. synthesize beauvericin and bassianolide , a variety of beauverolides (cyclic peptides), oosporein (dibenzoquinone), bassiatin (diketomorpholine), and tenellin (2-pyridone) [B. bassiana genes involved in toxin production inside different insect orders as the infection progresses, to help understand how these toxins participate as virulence factors, antimicrobials, or immunosuppressives within the context of a fungus–insect interaction.The fungus and host . Upon thhemocoel     ,5,7. TheMetarhizium spp. [Beauveria spp. [Searching the information available reveals some clues, but no conclusive evidence, that entomopathogenic fungal secondary metabolites are produced within the insect as part of the infection process. A metabolomics approach found differences in secondary metabolite production on both live and dead tissues, assigning different purposes to different compounds; i.e., beauverolides are involved in killing the host, and destruxins mainly function as antimicrobials . Oosporeium spp. ,14 or Beria spp. . Howeverria spp. . A majorMetarhizium ssp. and B. bassiana have no identified specific products, and their sequences are unique to entomopathogenic fungi [B. bassiana, e.g., tenellin, beauvericin, oosporein, and bassianolide. Functional studies targeting B. bassiana NRPS and PKS have assigned very important functions in fungal development and virulence against insect hosts. PKSs are linked to asexual development and cell wall integrity; for example, the Bbpks11 gene acts in responses to oxidation, high temperature, and UV irradiation [Bbpks15 is necessary for the formation of conidia and blastospores [BbbslS) is very important [BbbeaS) participates, but its role is not key [BbtenS) does not contribute to virulence [BbopS1) seems to directly participate in the evasion of insect immunity, and facilitates fungal growth [BbSmr1 negatively regulates oosporin production [BbbrlA gene [B. caledonica cultures [B. bassiana, it was proposed that the environmental signal for NRPS expression mainly comes from the insect host, and thus, there is a group of fast-evolving NRPSs  that are closely associated with pathogenesis [Secondary metabolites are synthesized from gene clusters, including nonribosomal peptide synthetases (NRPSs), polyketide synthetases (PKSs), and hybrid NRPS–PKS genes ,18. Theiic fungi . Althougadiation , and Bbptospores . Regardimportant , the bea not key , the tenirulence , and oosl growth . More deoduction  by bindirlA gene . Using lcultures . The dircultures ; similarcultures . For othcultures . The keycultures . The biocultures . Little ogenesis . In summogenesis ,31, althB. bassiana genome harbors 21 NRPS or NRPS-like genes [B. bassiana’s secondary metabolites in effecting the fungus’ fitness and virulence. Of the 21 predicted NRPSs, two of them seem to have unknown functions, and the rest have been putatively categorized into two functional groups: seven NRPSs might be important during both saprophytic and pathogenic lifestyles and, thus, be related to basic metabolism (group I), and 12 NRPSs are likely to be involved in pathogenicity (group II), which includes the well-characterized genes BbbslS and BbbeaS [B. bassiana ARSEF 2860 and the diamondback moth Plutella xylostella, these group II NRPS genes were not found to be expressed [BbbeaS, BbbslS, and BbtenS, as well as a gene that is speculated to encode a beauverolide synthetase (BBA_08222) [Galleria mellonella [BbopS1 is mainly expressed in insect cadavers at 24–48 h after death, reinforcing oosporein’s proposed role as an antimicrobial [The ke genes . A compake genes . Phyloged BbbeaS . In a duxpressed . Howeverxpressed , and allA_08222)  (Table 1A_08222)  and by tllonella . On the icrobial .B. bassiana’s expression of toxin genes peaked during the first days of infection, with the toxins perhaps functioning as virulence factors, and later in moribund insects and/or cadavers to protect them from competitive microorganisms [B. bassiana is also related to the fungal isolate: with the same insect as the host (the kissing bug Triatoma infestans), the strain GHA mainly expresses BbbeaS [BbbslS, with a lower levels of BbbeaS and BbtenS [The first detailed study on the expression of fungal genes involved in the biosynthetic pathways for secondary metabolites inside insects, as well as the host response, was developed by Lobo et al. . This abrganisms . The typs BbbeaS , but thed BbtenS   resulted a less virulent strain and impaired blastospore production in vivo [B. bassiana that were functionally characterized by reverse genetics [M. rileyi transition from yeast-like cells to mycelia, a process that begins with the host tissue invasion stage and then culminates with insect death. These authors demonstrated that neither the insect molting hormone, which prevents metamorphosis, nor some well-characterized quorum sensing modulators of these transitions in human pathogenic fungi, are involved in such a transition [In d BbabaA . Deletiod BbabaA . The entd BbabaA . A compatospores . The nul in vivo . Howevergenetics ,23,24, rgenetics ,47,48, igenetics  detectedansition . Thus, tansition . In concBbOpS1 delayed hemocyte encapsulation by 12 h, thus oosporein was linked with the evasion of insect host immunity. No functional information in this regard is available for the secondary metabolites biosynthesized by NRPS systems, except for some indirect clues contributed by phylogenetic analysis of BBA_07589, which has the same domain architecture as a siderophore synthetase exhibiting immunomodulatory activity in Aspergillus fumigatus [B. bassiana [Insects display complex and sophisticated innate immunity, including both cellular and humoral responses, protecting themselves from pathogens ,50. The umigatus ; thus, ibassiana .B. bassiana-infected larvae have demonstrated the induction of several immunity-related genes, including those for AMPs in G. mellonella [Ectropis obliqua [Helicoverpa armigera [Ostrinia furnacalis [P. xylostella, ~15% of the host genome was found to be enriched with genes for various immune processes [B. bassiana–T. infestans interacting system. The expression of six defensin genes in this insect host is modulated by two variants of the limpet transcription factor, and the silencing of both variants renders T. infestans more susceptible to B. bassiana infection [Transcriptomics approaches in llonella , hemocyt obliqua  and Heliarmigera , and in rnacalis . Furtherrocesses . Detailenfection . The expnfection ,37, i.e.The study of genes encoding NRPSs, PKSs, or hybrid NRPS–PKS proteins within insects is a useful approach for exploring the role of fungal secondary metabolites during pathogenesis. The NRPS expression signatures seem to be specific for fungal isolates, as suggested by qPCR studies ,36,37. H


The treatment of patients with cystic fibrosis involves the use of ototoxic drugs, mainly aminoglycoside antibiotics. Due to the use of these drugs, fibrocystic patients are at risk of developing hearing loss.To evaluate the hearing of patients with cystic fibrosis by High Frequency Audiometry and Distortion Product Otoacoustic Emissions.Cross-sectional study. The study group consisted of 39 patients (7–20 years of age) with cystic fibrosis and a control group of 36 individuals in the same age group without otologic complaints, with normal audiometric thresholds and type A tympanometric curves. High Frequency Audiometry and Distortion Product Otoacoustic Emissions tests were conducted.p = 0.004) as well as higher prevalence of otoacoustic emission alterations at 1000 and 6000 Hz (p = 0.001), with significantly lower amplitudes at 1000, 1400, and 6000 Hz. There was a significant association between alterations in hearing thresholds in High Frequency Audiometry with the number of courses of aminoglycosides administered (p = 0.005). Eighty-three percent of patients who completed more than ten courses of aminoglycosides had hearing loss in High Frequency Audiometry.The study group had significantly higher thresholds at 250, 1000, 8000, 9000, 10,000, 12,500, and 16,000 Hz (A significant number of patients with cystic fibrosis who received repeated courses of aminoglycosides showed alterations in High Frequency Audiometry and Distortion Product Otoacoustic Emissions. The implementation of ten or more aminoglycoside cycles was associated with alterations in High Frequency Audiometry. Cystic fibrosis (CF) is the most common autosomal recessive genetic disease among white patients. It affects the exocrine glands, which, when producing abnormally viscous secretions, cause a series of manifestations, mainly respiratory and digestive.6Among the main agents for cochlear alteration through ototoxicity are AG (aminoglycoside) antibiotics, widely used in the treatment of CF to combat colonization by bacteria. Due to the frequent use of this type of drug, patients with cystic fibrosis are at high risk of developing hearing loss.10The hearing monitoring of patients exposed to ototoxic agents aims to detect hearing loss before the occurrence of impairment at the range of frequencies corresponding to speech, with consequent damage to communication; and to enable an early audiological intervention through individual hearing aids and speech therapy in those cases in which hearing loss is already evident.HFA evaluates pure tone air conduction thresholds in the 9–20 kHz range, depending on the equipment. This is an important test for the early detection of hearing loss caused by damage to the base of the cochlea, as occurs in cases of ototoxicity, because it allows the detection of hearing loss before reaching the conventionally measured frequency range (250–8000 Hz).16The literature presents some studies on CF patients evaluating hearing by HFA. Fausti et al.Examination by OAE does not require that the patient provides responses, and this test is very suitable for small children and even for adults unable to respond to tests such as audiometry.In a study of CF patients and a control group, Mulheran et al.29In Brazil, there are few studies on CF patients’ hearing utilizing high frequency audiometry. Therefore, this study aimed to evaluate hearing thresholds testing high frequencies and using DPOAE in CF patients from this institution.This study was approved under No. 120096 by the Ethics Committee of the institution.This was an observational, cross-sectional study. The population studied was composed of a study group (SG) with 39 children and adolescents referred from adult and pediatric cystic fibrosis (CF) outpatient clinics from this institution. The control group (CG) comprised 36 children and adolescents from the institution's otorhinolaryngology outpatient clinic, trainees, and children of employees of the institution and students of a state elementary school.The inclusion criteria for the study group were as follows: individuals with a confirmed diagnosis of CF, aged 7–20 years, treated at the CF outpatient clinic, with type A tympanometric curvee.g., meningitis, acoustic trauma, tinnitus, otorrhea, history of recurrent otitis media in early childhood), family history of hearing loss, type B or C tympanometric curve,Exclusion criteria for study and control groups were as follows: individuals with illnesses associated with ear repercussion , with tympanometry and a survey of contralateral acoustic reflexes. The pure tone and high frequency audiometry tests were performed with the Siemens Unity PC audiometer (Germany), calibrated in dB HL according to ANSI standard 3.6-1989 with the use of HDA 2000 air and bone conduction B-71 phones. Pure tone audiometry by air and bone conduction was performed at 250–16,000 Hz and at 500–4000 Hz, respectively. All audiological tests were performed by two trained speech therapists using the same evaluation protocol.The criteria of normality used for pure tone audiometry were the International Bureau for Audiophonology  classification, in which the average of the frequencies of 500, 1000, 2000, and 4000 Hz <20 dB HL is considered as normal hearing. For high frequencies , thresholds up to 25 dB HL were used as a criterion of normality, as documented in previous studies of normal hearing individuals.34The distortion-product otoacoustic emissions test was conducted in an acoustically treated room with the ILO 292 system (Otodynamics – England). The examination was performed in the frequencies of 1000, 1500, 2000, 3000, 4000, and 6000 Hz. A probe was inserted into the patient's ear, with an audible stimulus simultaneously generated by two pure tones of different frequencies (F1 and F2), in which F1 = 65 dB, F2 = 55 dB, and F2/F1 = 1.22. The test was analyzed by a DP-gram chart, and presence of response was considered as the finding of amplitudes equal to or greater than 3 dB SPL above the noise level.Quantitative variables were expressed as mean and standard deviation or median and interquartile range. Categorical variables were described by absolute and relative frequencies.t-test for independent samples was applied. In the case of asymmetry, the Mann–Whitney test was used.To compare means between groups, Student's In the comparison of proportions, Fisher's exact test was used.p ≤ 0.05) and analyses were performed using SPSS software, version 18.0.The significance level was set at 5% (The sample consisted of 75 subjects: SG = 39 and CG = 36. The mean age was 13.0 (±3.2) and 12.3 (±4.1) years for the SG and CG, respectively. The participants’ age range was 7–20 years. Twenty-two subjects in the SG (56.4%) and 12 in the CG (33.3%) were male. There was no statistically significant difference in age and gender variables between the SG and CG, indicating that the subjects were similar in these aspects. Therefore, the sample was analyzed without reference to these variables. In the analysis of auditory thresholds between right and left ear, a statistically significant difference was noted only in the frequency of 250 Hz in the SG; in other frequencies and in the CG there was no such a difference. For this reason, the ears were analyzed with the use of their means at each frequency.When auditory thresholds were compared between groups, the SG had significantly higher thresholds at 250 Hz, 1000 Hz, 8000 Hz, 9000 Hz, 10,000 Hz, 12,500 Hz, and 16,000 Hz. The mean values at 250–8000 Hz and at 9000–16,000 Hz were significantly higher in the SG .Table 2Cp = 0.004)  . Using Pp = 0.001), as shown in The SG showed a significantly higher prevalence of DPOAE alteration when compared to the CG (p > 0.20).The SG presented more DPOAE alterations at 1000 Hz and 6000 Hz in both ears , when cop = 0.037).When comparing DPOAE amplitudes between groups, the SG had lower amplitudes at 1000 Hz, 1400 Hz, and 6000 Hz . When cop = 0.131)  and in the group with HFA alterations (91.7%), albeit more often in the latter. However, the statistical analysis showed that there was no association between changes in HFA and in DPOAE for SG participants (= 0.131) .Figure 3p = 0.005). The administration of more than ten courses of intravenous AG was associated with a higher prevalence of HFA alterations  and HFA  between groups, significantly higher thresholds were observed in the study group, with the largest differences occurring in HFA. Hearing loss was not observed in PTA; however, HFA detected high prevalence of hearing loss in the study group. These findings demonstrate the importance of using HFA in monitoring CF patients.40These results differ from those obtained by Martins et al.,vs. CG, even with normal hearing thresholds up to 8000 Hz. This finding supports the study of Stavroulaki et al.,In the present study, higher number of alterations by frequency and also lower amplitudes in DPOAE were noted in the SG When trying to establish a potential association between alterations in DPOAE and alterations in HFA, since the alterations in DPOAE occurred more frequently in individuals with alterations in HFA, this association was not found. This result may be related to the size of the sample. This finding disagreed with that of Arnold et al.,vs. individuals without the disease who were treated with AG, some authorsWith respect to AG effects, it is known that repeated courses of treatment and its duration are factors related to increased risk of ototoxicity.A significantly higher prevalence of DPOAE alterations in SG, with the presence of more alterations at 1000 and 6000 Hz in both ears and with lower amplitudes at 1000, 1400, and 6000 Hz, suggest that this test should also be conducted in CF patients, even in those with normal hearing. The significantly elevated hearing thresholds at 250; 1000, 8000, 9000, 10,000, 12,500, and 16,000 Hz and the exclusive presence of HFA alterations in 30.8% of the SG suggest that this assessment should be incorporated into the auditory monitoring of CF patients.This study showed that a significant number of CF patients who received repeated AG courses demonstrated HFA and DPOAE alterations, and that there was a significant association between administration of more than ten intravenous AG courses and a higher prevalence of HFA alterations.10.13039/501100003593CNPq.This study was funded by The authors declare no conflicts of interest.


Hearing loss is an important public health problem. Its causes vary, including infections, noise, and aging. The first wave of the COVID-19 pandemic occurred in April 2020 in Japan. During the pandemic, people were urged to stay at home and drastically changed their lifestyles. This study aimed to examine hearing loss before and during the pandemic. The prevalence during the pandemic after April 2020 was compared for the period in 2019. Study subjects were those who received health checkups in both periods. Hearing loss was defined as a hearing threshold of > 30 dB at 1 kHz and > 40 dB at 4 kHz in either ear using pure-tone audiometry.A total of 2367 persons presented in both 2019 and 2020. The overall rates of hearing loss were 9.5% and 13.2% before and after the pandemic, respectively. After controlling for age, sex, current smoking, regular exercise and alcohol consumption, the rate of hearing loss showed a significant increase in 2020 (p =  < 0.0001). With age stratification, an increase was observed in the participants aged < 40 years  and 40–59 years . Further studies are needed to confirm the impact of the COVID-19 pandemic on hearing loss.The online version contains supplementary material available at 10.1186/s13104-022-06120-1. Hearing loss is a major public health issue. It is caused by infections, exposure to loud sounds, chronic diseases, and aging. Recently, the overuse of earphones has been associated with the development of hearing loss . A worldThere are reports of substantial lifestyle changes during the COVID-19 pandemic. The Government of Japan has been promoting remote work, and many workers changed to remote work during the emergency declaration . A studyThere have been emerging publications on sudden sensorineural hearing loss after COVID-19 infection –12. All The current study aimed to examine hearing loss before and during the COVID-19 pandemic by comparing the prevalence among participants in regional health checkup centers in Japan. Furthermore, this study aimed to clarify any subgroups whose hearing ability may have been affected, e.g., different age groups show different situations of hearing loss before and during the pandemic. Lifestyle-related information was also examined to determine its association with hearing loss.Persons who received health checkups conducted in a regional health care center in Mito, Japan, were invited to participate in the study. All persons with hearing ability measurements were included in the study. Health information for the pandemic period came from the period of April 2020–March 2021 (we denote as “2020”) and for the prepandemic period of April 2019–March 2020 (we denote as “2019”). Study subjects were those who received health checkups in both periods.The information used for the analysis included the date of health examination, age, sex, body mass index (BMI), and medical history, which included medication use for hypertension, diabetes, and dyslipidemia, and history of stroke and heart disease. Self-reported information on current smoking, alcohol consumption, and regular exercise were also collected and analyzed. Regular exercise was defined as > 30 min/day and > 2 times/week based on a standardized questionnaire for lifestyle-related diseases by the Ministry of Health, Labour and Welfare, Japan.Pure-tone audiometry was conducted by trained medical staff using an AA-57 or AA-58 audiometer . Hearing loss was defined as a hearing threshold of > 30 dB at 1 kHz and > 40 dB at 4 kHz in either ear, according to the National Health Examination Guidelines .For the characteristics of the study participants, McNemar’s test and paired t test for continuous variables were used for categorical variables and continuous variables, respectively, to examine the differences between the two periods. The analysis was further conducted with the stratification of age groups , and the differences in the prevalence between the two periods were examined. Lifestyle changes were examined for current smoking, alcohol consumption, and regular exercise and compared between the two periods using McNemar’s test. To compare the rate of hearing loss between the periods, a generalized estimating equation (GEE) with repeated measures by examination year was used, and showed parameter estimates with 95% confidence intervals (95% CIs). The final model included variables of examination period (2020 vs. 2019), age (continuous), sex, current smoking, alcohol consumption, and regular exercise. Statistical analyses were performed using IBM SPSS Statistics version 27. Statistical significance was defined as a two-sided p value < 0.05.Table By age stratification analysis, the rates of hearing loss in 2020 for participants aged under 40 years (1.3% (10/799) vs. 3.1% (25/799), respectively, p < 0.001) and participants aged 40 to 59 years (7.2% (78/1087) vs. 12.6% (137/1087), respectively, p < 0.001) were significantly higher than those in 2019  in 2019 vs. 22.4% (501/2234) in 2020, p = 0.032) and there were no significant differences in regular exercise and alcohol consumption between the two periods  = 1.404, p < 0.0001). Male sex was associated with a higher rate of hearing loss   with repeated measures of hearing loss, n=2345 .


Mucormycosis is a relatively rare infection but with a high mortality rate due to the difficult and time-consuming diagnostic and therapeutic process. The authors present the first case of rhino-orbital-cerebral mucormycosis, histologically and microbiologically proven, in a patient after COVID-19 infection in Bulgaria. Mucorales, class Zygomycetes [Rhizopus, Mucor, Rhizomucor and Lichtheimia (Absidia) species are most commonly associated with human infections [Rhizopus arrhizus (previously named Rhizopus oryzae) has been reported as the most common causative agent of mucormycosis and is responsible for approximately 70% of all cases [Mucormycosis  is an invasive, opportunistic disease caused by saprophytic molds belonging to the order omycetes . Rhizopufections . The terfections . Rhizopull cases . A seasoll cases . After cll cases ,7. Mortall cases . The casll cases .The authors present a case of rhino-orbital-cerebral mucormycosis in a patient after COVID-19 infection, hospitalized at the University Hospital in Varna, Bulgaria.A 66-year-old male with low socioeconomic status was admitted to the maxillofacial surgery clinic on 26 October 2021 because of a pronounced, painful infiltrate in the right side of the face for 10–15 days. The patient did not report any underlying diseases or risk factors. A month before admission, he was diagnosed with COVID-19 but was not hospitalized. No specific therapy for COVID-19 had been administered. The patient did not receive any immunosuppressive treatment.On physical examination, a pronounced infiltrate in the right facial half accompanied by reddened and edematous skin and moderately expressed exophthalmos on the right were documented. No visible pathological changes were observed in the oral cavity. At the time of admission, a blood glucose level of 10.60 mmol/l was found. Additionally, glucose and ketones were detected in the urine sample. During the hospital stay, the blood glucose varied between 7.74 and 16.76 mmol/l. After consultation with an endocrinologist, the oral antidiabetic therapy was adjusted to maintain blood glucose within the normal range. The CT scan detected infiltrates both in the right maxillary sinus and in the orbital floor, accompanied by proptosis of the right eye bulb . On follHistopathological examinations of the affected sinus and soft tissues (hematoxylin and eosin and periodic acid–Schiff staining methods) revealed rough nonseptate hyphae, some branching at right angles; hemorrhages and necroinflammatory debris were seen .Rhizopus spp. Additionally, Enterobacter cloacae, Candida glabrata and Candida zeylanoides were isolated from the tested clinical samples. After the diagnosis was established, amphotericin B was prescribed to be added to the antimicrobial therapy as an antimold agent. Unfortunately, soon after admission, the patient self-discharged, refusing the necessary surgical and antimicrobial treatment.Biopsy samples of the necrotic mucosa from the medial border of the sinus were sent for microbiological testing. Rough, nonseptate hyphae, branching at 90°, were observed on direct microscopic examination. Later, when the clinical materials were inoculated on Sabouraud dextrose agar and incubated at 30 °C for 48 h, the growth of white, fluffy mold was observed . Direct A summary of the major clinical symptoms, laboratory results and treatment is presented in The causative agents of mucormycosis are ubiquitous and found in soil, fruits, vegetables, household dust and organic matter. They can also be detected as colonizers of the upper part of the respiratory system and the distal parts of the digestive tract in healthy individuals . The incThe predisposing risk factors for developing mucormycosis (including CAM) are varied and include metabolic acidosis (particularly diabetic ketoacidosis), viral-mediated pancreatic damage (COVID-19-associated), prolonged and high-dose corticosteroid therapy, hematological malignancies, neutropenia, advanced age, solid organ or hematopoietic stem cell transplantation, chronic kidney disease, a prolonged intensive care unit stay and the use of deferoxamine, voriconazole and broad-spectrum antimicrobial agents ,25. AddiA study from India identifies diabetes as the primary predisposing factor for CAM . AnotherR. oryzae produces the enzyme ketone reductase, which mediates its ability to flourish at acidic pH and high glucose and ketone levels. Gale demonstrated experimentally that the serum of healthy individuals inhibits the growth of R. oryzae, whereas the serum of patients with ketoacidosis stimulates fungal growth [In immunocompetent individuals, cell-mediated immunity and the phagocytic cells have a leading role in controlling fungal infections. Hyperglycemia and low pH, associated with diabetic ketoacidosis, negatively affect the phagocytic properties of mono- and polymorphonuclear cells; thus, the intracellular killing of fungal spores is hindered . In addil growth . These fIron is an important factor in the development and invasion of the Mucorales molds. The low pH decreases the affinity of iron toward transportation proteins  and the increased concentration of free iron becomes toxic to phagocytic white blood cells, which play the main defense role against the Mucorales molds. The use of deferoxamine in some patients further aggravates the infection, since the chelator acts as a siderophore for the molds and their ability to digest iron increases significantly ,31. HypeThe presented clinical case demonstrates that the diagnosis of mucormycosis is complex and based on clinical symptoms, histological and microbiological studies and radiological examinations. Although the observed changes are not specific, the imaging studies significantly contribute to the correct diagnosis. In this clinical case, sinus invasion, dislocation and destruction of bone elements were found on CT scan.The presented clinical case strongly suggests that the microscopy of clinical samples, suspicious for mucormycosis, is an important diagnostic tool. The authors used periodic acid–Schiff, hematoxylin and eosin and Gram methods to confirm the diagnosis. The observation of nonseptate hyphae invading tissues is highly suspicious for mucormycosis. Broad, irregularly branched and nonseptate hyphae were observed. Sometimes they were twisted (ribbonlike) and branching at an angle of 90°. The presence of rhizoids and stolons allowed partial identification of the genus.Although the representatives of the order Mucorales grow rapidly on solid fungal media, positive cultures are found in only 50% of the cases. Despite the microscopic demonstration of hyphae in the biopsy samples, negative cultures are common. The most likely cause is the fragile nature of the hyphae and their rapid destruction when inoculating the material . The sucTreatment of mucormycosis includes several key factors: rapid diagnosis, management of the risk factors, surgical treatment and antimycotic therapy. Early (after achieving stable conditions) and aggressive surgical resection and debridement of the affected tissues is the recommended treatment for mucormycosis ,17. The To the best of our knowledge, this is the first report of COVID-19-associated mucormycosis in Bulgaria. In all individuals who have predisposing risk factors  and a history of previous COVID-19 infection, and who also report facial pain, swelling, blurred vision and nasal discharge, COVID-19-associated mucormycosis must be considered as a differential diagnosis, which is a strong argument for diagnostic and therapeutic actions to be taken in due time.Mucormycosis is a severe infection, often with a lethal outcome, caused by widely distributed molds.COVID-19 infection and its complications can be predisposing factors for mucormycosis.A complex diagnostic approach that includes various methods  is needed to diagnose mucormycosis.Adequate management of mucormycosis requires surgical treatment and antifungal therapy.


Hearing music inside our heads is frequent, however some hear it more vividly, constantly and involuntarily. Musical Hallucinations (MH), first described by Baillarger in 1846, are a complex type of auditory hallucination characterized by perception of melodies, music, or songs.This work aims to review the literature considering MH.Pubmed and Google Scholar search using MeSH term “musical hallucinations”MH occurs in 0.16% of the population. They´re usually perceived as frightening or annoying. Proposed mechanisms include spontaneous activity triggered by sensory deprivation from hearing impairment, like in visual hallucinations in Charles Bonnet syndrome, and some authors even include MH as a subtype of this syndrome. Indeed, 60% of all patients with MH have hearing impairment or deafness. Other less frequent causes include focal brain lesions involving the auditory pathway and cortex, temporal epilepsy, metabolic or drug intoxication. Psychiatric conditions are uncommon but not impossible, especially in affective disorders. MH most frequently consist in familiar tunes, sometimes of personal significance, religious songs , childhood songs, folk and popular songs from the radio - suggesting that musical perception is never unlearned but represents a “parasitic memory”, an unchangeable memory feature which can be experienced by relevant neuronal circuit stimulation. Most patients with MH were reported to have no extraordinary musical skills.MH are rare and strongly associated with hearing loss, though investigation of other causes should be sought. Treating the underlying cause is important but remission is not guaranteed.No significant relationships.


Fluorescence lifetime imaging microscopy (FLIM) evaluates the metabolic state of tissue based on reduced nicotinamide adenine dinucleotide (NAD(P)H) and flavin adenine dinucleotide (FAD). Fluorescence lifetime imaging ophthalmoscopy (FLIO) can image the fundus of the eyes, but cannot detect NAD(P)H. We used multiphoton FLIM to study the metabolic state of the retina in fixed eyes of wild-type mice C57BL6/J. We sectioned the eye using a polyacrylamide gel-embedding technique and estimated the percentage of bound NAD(P)H. We found that oxidative phosphorylation was the predominant metabolic state, particularly in the inner retina, when a fixed retina was used. We also demonstrated the feasibility of FAD imaging of the retina. In addition, we demonstrated that autofluorescence and various FLIM channels, such as hemoglobin, melanin and collagen, can be used to evaluate the structure of the retina and other parts of the eye without any special staining. Fluorescence lifetime imaging microscopy (FLIM) displays the fluorescence lifetimes of various fluorophores in a sample as a two-dimensional image. Unlike intensity-based images, fluorescence lifetimes depend not on the fluorophore concentration but on the local environment. The same fluorophore could have different lifetimes based on its interacting molecule . Using FFLIM has been used to study eyes. Some studies have used fluorescence lifetime imaging ophthalmoscopy (FLIO), a combination of FLIM and confocal laser scanning ophthalmoscopy, to image eyes in vivo; however, NAD(P)H cannot be imaged by FLIO ,11,12,13All procedures complied with Institutional Animal Care and Use Committee (IACUC) guidelines at the University of Southern California. Wild-type mice (C57BL6/J) were purchased from Jackson Laboratories . Mice were housed in a 12-h light/dark cycle and food and water were provided ad libitum.Animals were euthanized, and the eyeballs were enucleated. Eleven eyes were included in the study. Before enucleation, the superior portion of the cornea was marked with cautery to preserve the orientation of the eyeballs. The eyeballs were punctured and placed in 4% paraformaldehyde for one hour. The corneas were then removed and the eyecups were placed in 4% paraformaldehyde for two hours.The eyecups were embedded in polyacrylamide gel, based on Hayaran et al.’s method . The gelThe Leica SP8 DIVE FALCON  was used for imaging; the samples were excited at 740 nm for metabolic and intrinsic autofluorescence signal imaging and 860 nm for second harmonic generation (SHG) at ~500 μW laser power for each wavelength. Autofluorescence was collected on three channels of hybrid detectors: 425–475 nm for NAD(P)H, 502–577 nm for flavin adenine dinucleotide (FAD), and 600–650 nm for hemoglobin and melanin. The NAD(P)H signal was excited through non-linear, multiphoton excitation by a Spectra Physics InSight X3 tunable IR laser  and emission was collected from 425–475 nm through adjustment of the Leica 4Tune NDD filtering system . Light of wavelengths 475+ nm was excluded from detection, because other autofluorescent molecules, such as FAD, are multiphoton excitable at 740 nm and we wanted to exclude those signals in our analysis of NAD(P)H. The SHG of collagen was collected from 411 to 463 nm. The choice of excitation and emission spectra were based on our previous work and the work of others ,18,19. WThe vertical sections were divided into a superior and an inferior region, and the horizontal sections were split into temporal and nasal regions. Each region was classified into five zones: far periphery (near the ora serrata), mid periphery , peripapillary (200 μm from the optic disc), central (400 μm from the optic disc), and paracentral (600 μm from the optic disc). Each zone was divided into outer (photoreceptor inner (IS), outer segments (OS), and outer nuclear layer (ONL)), inner (outer plexiform layer (OPL)), inner nuclear layer (INL), inner plexiform layer (IPL), ganglion cell layer (GCL), and retinal nerve fiber layer (RNFL)). The phasor approach to FLIM analysis  to deterTo determine the phasor position for hemoglobin, we selected an ROI in images corresponding to a retinal blood vessel, and by using the phasor ROI selection tool, we then highlighted all pixels within a retinal image containing that specific phasor lifetime position for hemoglobin.t-tests were used to compare the percentage of bound NAD(P)H. The mean, standard deviation (SD), and SEM for the percentage of bound NAD(P)H were obtained. Two-tailed paired p < 0.0001).In the NAD(P)H channel (425–475 nm emission spectra), we compared the percentage of bound NAD(P)H between the outer retina (photoreceptor inner and outer segments and outer nuclear layer) and the inner retina  . The zonp = 0.36). In the outer retina, the mean ± SD bound NAD(P)H percentage was 58.8 ± 2.6 in the far periphery and 58.2 ± 4.1 in the central zones (p = 0.64) (n = 15) H in the far periphery with the central zones to determine whether the density of photoreceptors and ganglion cells has any effects on metabolic activity . The com(n = 15) B. NeitheWe were also able to image FAD, which could also be used to study metabolic state. For the FAD imaging, we used 502–577-nm emission spectra .Autofluorescence images could determine the retinal structure by delineating the retinal layers. All the retina layers could be visualized, except the internal limiting membrane and the external limiting membrane. We also visualized a distinct band of relative hypo-autofluorescence in the inner plexiform layer, which is not visible on bright-field microscopy or common structural retinal staining, such as Haematoxylin and Eosin, and Periodic Acid Schiff . Using mWe could detect hemoglobin signals within the retinal and choroidal vessels when imaged with 600–650 nm emission spectra. A 3D image of the retina with several Z-sections demonstrated a deep capillary plexus in the outer plexiform layer, a superficial capillary plexus in the junction of the inner nuclear layer and inner plexiform layer, and a superficial layer composed of retinal vessels in the ganglion cell layer . In addiFLIM could also be used to study melanin. The RPE and the choroid displayed the melanin signal with the same emission spectra (600–650 nm) A. The collagen channel could display the sclera, cornea, conjunctiva, episcleral tissue, optic nerve sheath, Bruch’s membrane, and iris stroma, all of which generate a second harmonic  due to tIn this article, we demonstrated that fixed mice eyes could be used for metabolic studies of the retina by measuring the percentages of free and bound NAD(P)H. We observed higher percentages of bound NAD(P)H in both the outer and inner retina, indicating a predominance of oxidative phosphorylation throughout the retinal thickness. Comparing the inner and outer retina, we noted a greater number of free NAD(P)H in the outer retina, indicating a higher level of glycolysis in the outer retina relative to the inner retina. The bound NAD(P)H percentages obtained in our study are specific to fixed retina. Since a previous study demonstrated that fixation increases fluorescence lifetimes, further studies are required to evaluate any differences between fresh and fixed retina . SimilarWe showed that a metabolic image of the retina could also be obtained with the FAD channel. However, in our study, we did not determine the fraction of bound and free FAD for our samples, since our focus was to determine the metabolic state of the retina using NAD(P)H. Previous studies have used FAD to study the metabolic state of cancer cells. Imaging with the FAD channel and the NAD(P)H channel can potentially be used to determine the ratio of bound NAD(P)H to bound FAD, which estimates the redox state of the tissue ,28,29.Using multiphoton FLIM, in addition to metabolic imaging, we performed structural imaging of the retina. We also showed that FLIM can be used for structural imaging of the sclera, cornea, choroid, optic nerve sheath, and the tissues surrounding the eyes, without any staining. FLIO can also be used to study the structure of the retina; however, unlike FLIM it cannot detect NAD(P)H in the fundus. This is due to the short emission spectra and excitation wavelength of NAD(P)H, and these short wavelengths are obstructed by the cornea and lens ,11. The In FLIM, the hemoglobin channel can display retinal blood vessels well, particularly when a 3D video is generated from a thick retinal section. However, the vessels appear to be interrupted; this is due to the segmentation of the blood in the retinal vessels and capillaries, which occurs in tissues postmortem . SimilarFLIM also allows for the study of melanin distribution. In our study, a band of melanin signal corresponded to the RPE. Melanin signal was also detected in the choroid. Imaging melanin can be used to study diseases that affect the RPE, such as age-related macular degeneration and inherited retinal diseases.This study demonstrated the additional possibility of imaging collagen by generating a second harmonic. We most likely detected type I collagen, since fibrillar collagen generates a second harmonic, and type I produces a prominent second harmonic ,38. In aA limitation of this study is that the imaging was performed on fixed tissues. We used fixed eyes for two reasons: (1) the soft consistency of the unfixed retina made it cumbersome to section, and (2) imaging the fresh retina resulted in artifacts; the fresh retinal sections disintegrated and the retinal architecture became distorted. We fixed the eyes by immersing in 4% paraformaldehyde for a total of 3 h.In summary, our study determined the metabolic states and structure of fixed eyes from wild-type mice. We found that oxidative phosphorylation is the predominant metabolic state in the retina, but the outer retina shows significantly less oxidative phosphorylation than the inner retina. In addition, we were able to better localize hemoglobin that is present in the RPE. Multiphoton FLIM allowed for the study of the whole eye using NAD(P)H, FAD, hemoglobin, melanin, and collagen channels. In the future, with additional strategies, metabolic states of various disease models in mice can be determined using this study as a baseline.


The prognostic significance of vertigo in patients with idiopathic sudden sensorineural hearing loss (SSNHL) remains a matter of debate.This paper aims to verify the difference between a group with vertigo and a group without vertigo, and to analyze vertigo's validation as a prognostic factor in patients with SSNHL.t-test was used to compare group A  and group B . Also we want to verify the interaction effects between vertigo and other prognostic factors using multiple regression analysis.This study involved 183 patients with SSNHL. A There was a significant difference between group A and group B: the initial hearing level of group A was lower than group B, and their treatment onset was also shorter. In addition, vertigo itself didn't affect hearing improvement, but the interaction variable between vertigo and initial hearing level did affect hearing improvement significantly.The clinical characteristics of patients with vertigo did not directly affect hearing improvement with SSNHL; however, vertigo had an influence on SSNHL though its interaction with the initial hearing levels. Sudden sensorineural hearing loss (SSNHL) is a loss that is greater than 30 dB in three contiguous frequencies and that occurs in less than 3 daysA maximum of 32% to 65% of cases of SSNHL may recover spontaneously. Prognosis for recovery is dependent on a number of factors, including patient age, presence of vertigo at onset, degree of hearing loss, audiometric configuration, and time between the onset of hearing loss and treatment. Even though some studies have reported vertigo as a prognostic factor to SSNHL, it is often considered a poor prognostic factor and the effect of vertigo as related to SSNHLThis study used the medical records of 183 patients with SSNHL. All patients experienced idiopathic unilateral sensorineural hearing loss that developed within 3 days and excluded other known pathologies, including Meniere's disease, autoimmune disease, ototoxicity, or neoplasm.The patients had a minimum hearing loss of 30 dB at three consecutive frequencies. Patients received steroid treatment (injection of prednisolone 60 mg/kg for six days then tapered over four days) started concomitantly with low molecular weight dextran, and checked 3 months after treatment. This study was approved by the institution's Ethics Committee and given permit number EU12-31.The hearing loss classification was as follows: mild (26~40 dB), moderate (41~55 dB), moderately severe (56~70 dB), severe (71~90 dB), and profound (over than 91 dB). The SiegelPatient characteristics and clinical details are given in t-test was performed to identify statistically significant differences between group A  and group B . Multiple regression analysis was used to find prognostic factors associated with hearing improvement, and analyze the interaction effects of vertigo.Statistical analyses were carried out with PASW Statistics ver. 18.0. A t-test results revealed that no significant difference in SSNHL between the two groups existed; however, a significant difference of 0.05 was found in the initial hearing level and treatment onset, as shown in The In addition, multiple regression analysis was used to identify predictors of hearing improvement in patient with SSNHL. Treatment onset, initial hearing level, and vertigo were used as independent variables while hearing improvement based on Siegel's classification was used as dependent variables. In the regression analysis results in We analyzed the interaction effects between vertigo and initial hearing (or treatment onset). After including interaction variables , we investigated the following equations using multiple regression analysis.As shown in the results in This research focused on the prognostic factors associated with SSNHL. Initial hearing level, treatment onset and vertigo were investigated as prognostic factors. We also analyzed the interaction effects of vertigo, which was not verified clearly, as a prognostic factor of former research.Firstly, following the comparison results between group A  and group B , initial hearing level and treatment onset were significantly different between the two groups at the 0.05 level, but SSNHL was insignificant. This result supports Ahn et al.Secondly, from the results of the multiple regression analysis, initial hearing level and treatment onset were significant to hearing improvement while vertigo was insignificant. In the former researches, the initial hearing level negatively affected SSNHLp < 0.01). Especially, there were debates over whether vertigo was a prognostic factor toward hearing recovery rate. SheehySiegelFinally, we carried out research to verify the interaction effects between vertigo and other independent variables . The research results showed that vertigo did not affect SSNHL directly, but we found interaction effects between vertigo and initial hearing level. This result supported former studiesThis research has a value to verify that the treatment onset and the initial hearing level affect hearing improvement. More important contribution is to find the interaction effects of vertigo and initial hearing level to predict hearing improvement with SSNHL patients. That is, it supports former research studiest-test was used to compare between group A  and group B  with data from 183 patients, and multiple regression analysis was conducted. The results showed that vertigo did not directly affect SSNHL. However, there is considerable evidence of interaction effects between the initial hearing level and vertigo.This research analyzed prognostic factors associated with hearing improvement with SSNHL. A


Retroreflectors are ubiquitously used in a multitude of applications, such as cloaking, wireless communication, radar, and antenna, owing to their ability to augment the reflected electromagnetic (EM) waves in the incident direction. However, Current metasurface retroreflector designs have yet to mature into a practical method due to the limitations of low efficiency and narrow band, which actually originate from the difficulty in simultaneously engineering phase profiles of certain metasurface at distinct wavelengths. Here, a broadband spin‐locked retroreflector with high efficiency that relies only on a simple metasurface layer is demonstrated. The metasurface is designed with low‐loss dielectric resonators, introducing both the propagation and geometric phases to enable dispersive phase compensation. The results indicate that the proposed metasurface can achieve retroreflection over a broadband spectrum while keeping the spin state identical. Furthermore, a broadband spin‐locked cloak is presented for validation. The work builds up a major advance for practice‐oriented retroreflector and even envision this approach may open new vistas in the very cutting‐edge research of 6G wireless communication network. A broadband spin‐locked retroreflector is demonstrated with high efficiency that relies only on a single‐layer metasurface. The metasurface is designed with low‐loss dielectric resonators, introducing both the propagation and geometric phases to enable dispersive phase compensation. With the development of metamaterial, arbitrary controlling propagation of waves has been possible. In recent years, metasurfaces have emerged as versatile platforms owing to their excellent ability to manipulate light. Because the phase of the metasurface can be accurately controlled by subwavelength‐scale structures, many optical functional devices and applications, including metalenses, polarization convertors, holograms, and cloaking, have been demonstrated. Moreover, the advent of metasurfaces has made feasible the realization of extremely thin retroreflectors. Furthermore, metasurfaces with spin‐based applications have attracted significant interest owing to the cutting‐edge research field of spin optics. The spin of light refers to the right‐ and left‐handed circular polarization (RCP and LCP) of a light beam, where the handedness depends on the direction of propagation. Spin‐locked retroreflectors based on metasurfaces have been reported, but they are limited to a single wavelength or very narrow spectrum. Additionally, experimental work on spin‐locked metasurface retroreflectors in broadband spectrum is still elusive.Retroreflector is an important electromagnetic (EM) device or surface that can reflect incident EM waves back as it comes. It has attracted significant research attention owing to its advantages in communication systems, remote sensing technology, directional energy transmission and so on. Conventional retroreflectors are typically designed using corner reflectors1, 2Here, we demonstrate a broadband spin‐locked retroreflector with high efficiency, which employs the low‐loss resonant unit element in metasurface with smooth and linear phase dispersion. This is made possible by combining the propagation and geometric phases to implement dispersive phase compensation. The proposed retroreflector maintains the handedness of the reflected waves, which is the same as the incidence. The simulated and experimental results prove the feasibility of the broadband spin‐locked retroreflector concept. Moreover, a spin‐locked cloak based on the designed retroreflector is demonstrated to restore completely the distorted phase of EM waves caused by bumps in the broadband spectrum. The proposed retroreflector has great practical potential in wireless communication systems that utilize spin‐based retroreflection devices.2 for retroreflection, θi = −θr, where θi is the incident angle and θr is the angle of reflection. We can obtain the angle of reflection asλ is the wavelength of the EM wave, dϕdx is a suitable phase gradient, c is the velocity of light in vacuum, f is the working frequency, Δϕ(f) is the phase shift between two adjacent unit cells along the interface, and p is the period of the unit cell. To realize broadband retroreflection, Equation  and relative permittivity of 4.3 + 0.004i. The backside of the unit cell is a metallic plane. The period, p, is set to 10 mm. This single‐layer metasurface can accurately meet the requirement of desired phase distribution by simultaneously adjusting propagation and geometric phases. For the propagation phase alone, the reflected phase gradients can be changed by adjusting the structural parameters  of the RPR, where Figure α, refer to Supporting Information) at fixed structural parameters. As can be seen in Figure To solve the crucial issue of the phase profiles required in Equation , we desiFigure Δφ(f)f=6 (°/GHz). Moreover, the conversion efficiency is >80%, which guarantees the spin‐locked characteristic. A schematic of the proposed broadband spin‐locked retroreflector is shown in Figure A schematic of the designed unit cell is shown in the inset of Figure xoz plane at 8, 9, and 10 GHz. As expected, the very clean beam‐bending signature and the exact deflection angle of 14.5° reinforce our notion of achromatism over a wide bandwidth. Figure xoz plane under RCP incidence with an incident angle of 14.5°, which demonstrates the spin‐locked feature of the designed retroreflector. Furthermore, the far‐field patterns of the spin‐locked broadband retroreflector are experimentally investigated. The SRR and RPR are printed on a 2 mm epoxy glass cloth copper‐clad laminate with a permittivity of 4.3, there are 30 unit cells along the y direction. The far‐field experiment is carried out in an anechoic chamber. RCP waves from the circularly polarized horn antenna are obliquely incident on the retroreflector with the incident angle of 14.5°. Another circularly polarized horn antenna works as the receiver to measure the scattered fields with a distance of 2.0 m. All the scattered intensities are normalized to their own maxima to improve the presentation of the scattering direction. Figures  At the target frequency band, the absolute efficiencies of the designed retroreflector range from 81% to 91%, as retrieved from our experimental results. The slight difference between the simulation and experimental results may be attributed to inevitable fabrication errors. All of the aforementioned results verify the feasibility of the designed spin‐locked retroreflector for broadband spectra.The metasurface is feasible for realizing retroreflection of the broadband spectrum while locking the spin characteristics of the EM waves. Based on Equation , a spin‐ Figures 62 At Figurexoz plane (the sample is symmetric ≈y = 0) over the samples are measured. Figure Moreover, we build a broadband spin‐locked metasurface cloak using the designed retroreflector. 3In summary, we demonstrate a broadband retroreflector made of ultrathin spin‐locked metasurfaces working at 8–10 GHz with high efficiency. The required phase profile of the unit elements for realizing broadband retroreflection is achieved by incorporating the geometric and propagation phases. The simulated and experimental results indicate that the designed retroreflector has a good performance within the broadband spectrum while keeping the spin state identical. Furthermore, we realize a broadband spin‐locked cloak that can restore the distorted phase of light by utilizing the designed retroreflector. Our design paves the way to a practical class of retroreflectors that can control the phase dispersion at will, and the demonstrated broadband spin‐locked retroreflectors are promising in the applications of spin‐based information transmission systems.The authors declare no conflict of interest.Supporting InformationClick here for additional data file.


Aim: to evaluate tinnitus after one month use of BTE hearing aids with open molds and pressure vent molds in patients with symmetric sensorineural hearing loss. Methods: 50 patients seen at our Tinnitus Clinic who presented bilateral tinnitus and hearing loss underwent a randomized blind crossover clinical trial: 26 first used BTE hearing aids with open molds, and the remaining 24 first used pressure vent molds. After 30 days using the first mold and a wash-out period, the type of earmold was changed and was applied for another 30-day-period. Tinnitus evaluation was done qualitatively  and quantitatively . Results: 82% of the cases reported improvement of tinnitus with at least one type of earmold; there was no significant difference in the reduction of discomfort due to tinnitus in the quantitative and qualitative evaluations. Although similar tinnitus control was obtained with both methods, 66% of the patients preferred the open mold. Conclusion: In a short-term evaluation improvement of tinnitus by the use of hearing aids does not depend on earmold ventilation.Hearing aids may be a option to improve tinnitus and hearing loss.  About 90% of tinnitus patients also have some degree of hearing loss.Hearing aids are routinely used to minimize the effects of hearing loss;Many patients, however, are not comfortable with the occlusion of the external acoustic meatus (EAM) by hearing aid earmolds. This occlusion effect is characterized clinically by a blocked ear sensation, annoyance with one’s own voice and with chewing noises,A relatively simple way to reduce the occlusion effect produced by earmolds on the EAM is to open a vent hole in parallel with the original earmold hole. Venting allows amplified low frequency sounds to escape, providing relief from the blocked ear sensation, a relative increase of the response to treble sounds and improved sound quality.Published papers that have defended the use of hearing aids for controlling tinnitus generally focus on evaluating the masking effect produced by hearing aid-amplified ambient sounds on tinnitus. These papers have rarely specified the diameter of the vent hole, the type of earmold, or the manner by which these aids were adapted to patients.With the advent of Tinnitus Retraining Therapy (TRT) in 1990,In our clinic we have observed that some tinnitus patients with sensorineural hearing loss, which had not improved satisfactorily with poorly vented hearing aids, attained better control of tinnitus with larger earmold vents. This finding motivated this study, where the main aim was to assess the response of tinnitus patients to behind-the-ear (BTE) hearing aids with two types of earmold vents (vented earmold and pressure vent), in patients with mild to severe sensorineural symmetric hearing loss, after one month of hearing aid use.Secondary aims were to check possible variations in the response of tinnitus to earmold vent types according to the audiometric configuration of hearing loss, and to assess the response of hearing loss to both type of earmold vents, correlating the tinnitus response with the hearing loss response.We conducted a randomized blinded crossover clinical trial in which the type of hearing aid earmold was exchanged during the study. Approval was obtained from the Committee for the Analysis of Research Projects of the Clinical Hospital of the Sao Paulo University Medical School (HCFMUSP) ; funding was provided by the FAPESP Support for Research Grants (process number 02/09199-0).The sample included 50 subjects, 28 (56%) women and 22 (44%) men, aged between 25 and 89 years, with a mean age of 64.4 years and a standard deviation (SD) of 13.1 years, registered in our Tinnitus Research Group.Inclusion criteria were as follows: the presence of bilateral constant tinnitus in adult subjects of both genders; the presence of bilateral symmetrical sensorineural hearing loss of any etiology in which hearing aids were indicated; awareness of the trial requirements and signing of a free informed consent form.Exclusion criteria were as follows: bilateral asymmetrical sensorineural hearing loss defined as a 15 dB difference in two or more frequencies; profound sensorineural hearing loss in two or more frequencies; mixed hearing loss; and a medical contraindication or refusal to try hearing aids.Hearing loss was assessed by pure tone audiometry before the study as one of the sample selection criteria. Upon inclusion, 37 (74%) patients presented hearing loss with a downward sloping audiometric configuration and 13 (26%) patients had hearing loss with concomitant low frequency involvement.-Quantitative assessment using a numeric scale (NS) from 0 to 10 to measure annoyance due to hearing loss; this test was applied before the trial and 30 days after household experience with each type of earmold.-Qualitative assessment using a closed question applied at 30 days of testing each type of earmold: “What happened to your hearing loss?” where the answer was chosen from the following options: “improved”, “unaltered “, or “worsened”.After inclusion, hearing was further assessed by free-field audiometry at 500, 1000, 2000 and 4000 Hz with and with no hearing aids after 30 days of household experience with each type of earmold. Benefits due to hearing aids were assessed by the following tests:Both hearing and tinnitus (annoyance) were assessed using quantitative and qualitative methods.Group 1received binaural adaptation of hearing aids with vented earmolds followed by earmolds with pressure vents.Group 2received binaural adaptation of hearing aids with pressure-vented earmolds followed by vented earmolds.The pre-inclusion assessment was conducted by the otorhinolaryngologist in charge of the Tinnitus Research Group based on a medical and audiological evaluation protocol used routinely in the clinic. After inclusion patients were monitored by the speech therapist in charge of the trial and randomly allocated to one of the following two groups:The patients were evaluated to classify annoyance due to tinnitus and hearing loss in a 0 to 10 NS before receiving a hearing with the first earmold. Each group of patients was instructed to use the hearing aids for 30 days. After this period a “blinded” to the trial speech therapist assessed all patients with free-field audiometry with and with no hearing aids, and conducted the quantitative and qualitative tests for tinnitus and hearing loss.After this first stage the patients were kept free of hearing aids for fifteen days (wash-out period) to eliminate any effect that the first earmold might have on the second earmold. Patients then used the second type of earmold for another 30 days, after which a similar evaluation was done by the same speech therapist “blinded” to the trial .Figure 1The earmolds were simple invisible rigid acrylic earmolds made by the same prosthetic professional in two vent sizes as follows:Pressure vent: a 1mm diameter hole in parallel to the earmold hole, with the aim of balancing EAM and atmospheric air pressure;Vented earmold (maximum vent): a 4 mm diameter hole that drastically reduced the amplification of frequencies below 1000 Hz.The patients were fitted with GnResound Danalogic model 163 BTE hearing aids to avoid any influence of hearing aid type on outcomes. The hearing aids had the following main features to allow flexibility for different audiometric configurations: 6 channels, 3 comfort programs, acoustic feedback digital suppressor, wide dynamic range compression, suppression of ambient noise and directional digital amplification.At the end of the trial, patients that responded favorably to hearing aid tests when using at least one of the earmold types were given the hearing aids free of charge.Statistical analysis included categorical variable frequencies, and measurement of the central tendency and dispersion for quantitative variables. The Wilcoxon test was used for quantitative measurements and the McNemar chi-square test was used for qualitative data. Spearman’s (f) correlation coefficient was also used. The statistical significance level was p ≤ 0.05.The mean tinnitus annoyance score before the trial went from 1 to 10 points, with a mean 7.1 points (SD: 2.2). The hearing loss annoyance score varied from 0 to 10 points, with a mean 6.2 points (SD: 2.4).The vented earmold was used initially in 26 patients (52%), followed by the pressure vent after the wash-out period. The remaining 24 patients (48%) started the trial using pressure vented earmolds followed by the vented earmold in the second part of the trial.There was no NS score difference in the quantitative assessment of tinnitus following the use of both vent sizes. The mean annoyance score was 3.7 with the vented earmold and 3.9 with the pressure vent (p=0.96). The qualitative assessment revealed that 41 patients (82%) reported improvement from tinnitus with at least one type of earmold. No significant difference was observed in the effect of earmold venting on annoyance due to tinnitus .The quantitative assessment of hearing loss showed that annoyance due to hearing loss tended to regress when using pressure vents compared to vented earmolds, although this trend was not statistically significant (p=0.11). The qualitative assessment showed that 46 patients (92%) reported improvement of hearing with both types of earmolds; 2 patients (4%) improved only with the pressure vent. No significant difference was found in the earmold venting effect over annoyance due to hearing loss .Grupo Dincluded patients with downward sloping hearing loss .Grupo Pincluded patients with flat configuration hearing loss and those patients in which lower frequencies were also affected .Patients were regrouped into two other groups to check whether the response of tinnitus to venting varied with audiometric configurations, as follows:There was no significant quantitative NS score difference in annoyance due to tinnitus in group D patients. Patients in group P tended to be less annoyed from the tinnitus when using the pressure vent (p = 0.08). There was no significant qualitative difference in annoyance due to tinnitus for both types of earmolds in both groups.The quantitative assessment of hearing loss showed that annoyance due to hearing loss tended to regress when using pressure vents compared to vented earmolds in group P patients. The qualitative assessment showed no significant difference in annoyance due to hearing loss when using both types of earmolds in both groups.There was a positive correlation between the variation of measurements of annoyance due to tinnitus and hearing loss assessed by the NS when using vented earmolds and pressure vents . The regVented earmolds were preferred by 66% of patients, regardless of having started the trial using vented earmolds or pressure vents. Twenty-six group D patients (70.3%) preferred vented earmolds; seven group P patients (53.9%) also preferred this type of earmold.Functional gain was significantly higher when using pressure vents at 500 Hz and 1000 Hz (p=0.03) in group P patients.Of the 50 patients involved in this trial, four (8%) refused hearing aids after the study; 3 were dissatisfied with the results and 1 was unable to handle the prosthesis adequately. These patients returned the hearing aids at the end of the trial and continue to be monitored at the Tinnitus Research Group of the HCFMUSP.Hearing loss may be the most important factor in the prevalence of tinnitus; both findings are age-related.Our study sample consisted mostly of elderly patients with ownward sloping sensorineural hearing loss (74%). Sheldrake and Hazell (1991) and Santos et al. (1999) have also shown that this type of audiogram occurs in about 60% of tinnitus patients.25Tinnitus tends to be mild and intermittent in 80% of cases, which does not produce significant negative consequences for individuals; these persons generally do not seek medical care for this reason. Hearing loss generally progresses slowly - as opposed to tinnitus, which usually appears abruptly - and may not be perceived in its initial stages. It becomes significant when communication is affected.The use of sound devices to relieve tinnitus dates from Aristotle, who toyed with the idea that a stronger sound could mask a weaker sound.21 When a patient also presents hearing loss, sound stimulation has to be done through hearing aids;32Von Wedel et al. (1989) compared the benefits of hearing aids and tinnitus maskers in 74 patients during three years and found total or partial masking of tinnitus with hearing aids in 80% of cases.33 Similar results were also presented by Moura et al. (2004), who showed improvement of tinnitus in 87.2% of 47 cases; in this study, there was total masking of tinnitus in 51% of patients after 3 to 8 months of hearing aid use.34 Folmer et al. (2002) found that hearing aids used during nine months reduced the intensity of tinnitus in 69% of 123 cases.31 Kiessling (1980) and Surr and Mueller (1985) reported satisfactory masking of tinnitus in 50% of patients wearing hearing aids for a few weeks.36During our 30-day study period we were able to see improvements in tinnitus due to partial or total masking in 82% of our sample. We considered this time-frame as a habituation period, without losing our focus which was to assess the benefit brought by hearing aids in the short-term improvement of tinnitus.Automatic masking of tinnitus in 82% of cases may be considered a satisfactory result compared to other forms of tinnitus therapy. We believe, however, that relief only occurs while using hearing aids; patients again perceive tinnitus as soon as the hearing aid is removed.Neuroscience investigation shows that CNS plasticity requires longer time periods, similar to the premise of Tinnitus Retraining Therapy (TRT), which is based on the neurophysiological model described by Jastreboff in 1990.16 In TRT the required time for habituation to tinnitus is about 18 months.Adaptation of hearing aids in TRT is indicated for patients that consider hearing loss a significant problem in their lives. The impact of hearing loss on the life of a patient is more important this his or her audiometric configuration.In TRT, non-occlusion of the EAM when adapting instruments (sound generators or hearing aids) is essential to assure the passage of ambient non-amplified low frequencies to the EAM, which favors the habituation process to tinnitus.40 Decreased annoyance due to tinnitus would be expected in the long-term for patients using vented earmolds. In our study we did not take into account the habituation process; we considered only the tinnitus masking effect produced by simple amplification of ambient sound. Furthermore, adaptation of hearing aids for TRT is only part of a complex process that also includes therapeutic counseling so that patients may understand the generation, detection and perception mechanisms of tinnitus. The main function of hearing aids in TRT it to act on the tinnitus detection process, enriching the patient’s sound environment.An advantage of this approach is habituation to the perception of tinnitus; although a prolonged period may be required, definitive improvements results from plastic changes in the CNS, where patients cease perceiving tinnitus in most situations of daily life. 71% to 87.5% of TRT category 2 patients , treated with therapeutic counseling and hearing aids, reported definitive improvement of tinnitus after one year of treatment.42Vented earmolds have been used frequently in hearing aid adaptation for downward sloping configuration hearing loss since the 1970s. A study on earmold preference (vented or unvented) showed that 83.3% of patients with sloping hearing loss preferred vented earmolds.Dillon (2001) and Voogdt (2002) reported the occlusion effect in patients with hearing loss under 40 dB NA at low frequencies (downward sloping configuration), and suggested that a 2mm vent could avoid occlusion, although vent sizes 3mm or above might be needed.Some authors have reported increased perception of tinnitus upon occlusion of the EAM, and have recommended vented earmolds for hearing aid adaptation.Valente et al. (1996) also found that adaptation to hearing aids with vented earmolds favors hearing aid acceptance and reduce the discomfort associated with EAM occlusion, regardless of tinnitus.Although the benefits of vented earmolds are unquestionable, there are caveats such as an excessive escape of lower and middle frequencies, which may reduce the gain of hearing aids at these frequencies in patients with flat configuration hearing loss where low frequencies are also affected.Possibly due to an excessive escape of lower frequencies, this same group tended to be less annoyed by tinnitus, as shown by the NS score for the pressure vent. Even so, 53.9% of these patients chose vented earmolds at the end of the trial. These findings are similar to those of Nielsen (1975), who also noted that 42.9% of patients in groups with the lowest thresholds at lower frequencies chose vented earmolds, explaining this choice as being due to greater comfort and improved sound quality.Although our findings did not confirm our original hypothesis that the vented earmold would be superior for reducing tinnitus in patients with hearing aids, our results indicate that significant relief may be obtained in patients with tinnitus (82%) and hearing loss (96%), which can positively affect the patient’s quality of life.Furthermore, we were able to show that regardless of the auditory configuration of hearing loss, earmold venting may be fundamental for successful adaptation; 66% of patients preferred the vented earmold rather than the pressure vent, possibly due to increased comfort. On the other hand we confirmed the idea that larger vents may reduce the functional gain of hearing aids at certain frequencies. As such, individual audiometric characteristics should be taken into account when choosing an earmold type. Over half of the patients with flat configuration hearing loss preferred the vented earmold at the end of the trial, showing that from the patient’s point of view, comfort may be more important than auditory gain.82% o patients reported reduced annoyance due to tinnitus and 96% reported improvement of hearing loss by using hearing aids with at least one type of earmold. There was no statistically significant performance difference in the quantitative and qualitative assessments of both types of earmold.Patients with a flat configuration hearing loss tended to present less annoyance from the tinnitus when using the pressure vent. Gain in function at 500 and 1000Hz was significantly higher with this type of earmold.A positive correlation was seen between measurements of variation of annoyance due to tinnitus and hearing loss when using vented earmolds and pressure vents.