This is a report of an 81-year-old woman presenting with hearing improvement after a reduction of antidepressant medication to manage a manic episode. The patient reported a subjective improvement in her hearing ability, not confirmed by audiometric testing. It was reported to us that she stopped using her hearing aids subsequently. This case highlights the potential for medications to impact hearing and the importance of monitoring for side effects in elderly patients with mood disorders. Hearing loss is a common issue in the elderly population and is often attributed to age-related changes and exposure to noise. However, the impact of medications on hearing has been increasingly recognized as a contributing factor. Hearing impairment is one of the most common disabilities in older adults. According to a recent report by the WHO, more than 1.5 billion people live with hearing loss .In this case report, we present an 81-year-old woman with a history of manic episodes, who experienced a subjective improvement in her hearing ability after the reduction of her antidepressant medication. This case sheds light on the importance of monitoring for potential side effects in elderly patients receiving psychotropic medication and highlights the need for further investigation of the relationship between mood disorders, psychotropic medications, and hearing function.An 81-year-old woman with a 26-year history of bipolar disorder presented to the community mental health team with symptoms of mania, including pressure of speech, elated mood, and lack of sleep. The manic episode lasted for two weeks at the time of the first assessment and was found to be precipitated by antidepressant medication. We did not find any evidence of delusions at the assessment. The past medical history included bipolar affective disorder, hypothyroidism, and osteoarthritis of the hips. The patient also had a 10-year history of bilateral SNHL. The medications were Lamotrigine, Mirtazapine, Olanzapine, Levothyroxine, Omeprazole, Zopiclone, and Fluoxetine. After the first assessment, Fluoxetine was stopped. Two weeks after the initial assessment, the Mirtazapine dose was gradually reduced from 45mg to 15mg in two weeks. After the reduction of Mirtazapine, the patient experienced a significant improvement in her hearing and stopped using her hearing aids during daily visits. At the follow-up assessments, she was able to communicate with the staff member without using her hearing aids. An audiology test was completed two weeks after the subjective improvement in her hearing and the result showed that her hearing has been the same for the last year.In one cohort study, all classes of antidepressants were found to increase the risk of SNHL. Increased numbers of different classes of antidepressants were associated with a high risk of SNHL . In anotAuditory perception is facilitated by the neural encoding of sound together with the transmission and processing of that information in the cortical and sub-cortical regions . In thisWe propose several hypotheses that may explain our patient's improvement in hearing. These are grouped into two: There was a physiological impairment that was not detected by the audiometry and there was no physiological impairment.There was a physiological impairment not detected by audiometryAudiometry involves pure tone tests but can also include other tests such as speech discrimination. We did not have further information on the tests that were performed but instead received a summary of the outcome from the patient on which we have based our considerations. If the audiometry involved speech discrimination then the possibilities below should be considered.Firstly, the effects of antidepressant treatment are likely mediated in part by changes in neural plasticity .The second hypothesis is that depression and mania influence hearing in this case via concentration. This in turn may improve speech discrimination even with the presence of partial hearing loss.Thirdly, there could be an iatrogenic effect. In our patient, altered serotonergic activity in the brain may change the activity in the auditory cortex or associated areas. In one study, the authors found that increased plasma serotonin levels were found to be a biomarker of sudden sensorineural hearing loss (SSNHL) . TherefoAlthough the audiometry test result did not show any difference from previous years, the patient reported significant improvement in her hearing level. These perceived changes resulted in her stopping using hearing aids, which she used for a long period of time.There was no physiological changeThere remains the possibility that the perception of improved hearing occurred without a physiological change. In this case, the perception may represent a reverse somatoform disorder whereby there is a perception of recovered function. This may also be a delusion occurring in the context of mania where there is an overestimation of abilities. The study period and available information were not sufficient to exclude these possibilities.As hearing impairment is a significant disability in the older adult population, this area needs further investigation. Although there are gaps in the information in our case, there are sufficient questions from the research literature to offer a framework for further considerations in this area.Hearing loss is very common in the older adult population and this can impact on quality of life. Hearing impairment is a significant problem globally and psychiatrists need to be aware of this when treating psychiatric problems. One of the drawbacks of the study was that we did not use the Naranjo algorithm. Psychosomatic causes of hearing loss in the older adult population are an area that would benefit from further research. Further research is needed into the role, if any of serotonin in hearing.


Hearing loss is a major public health problem with significant evidence correlating it with cognitive performance. Verbal fluency tests are commonly used to assess lexical access. They provide a great deal of information about a subject’s cognitive function. The aim of our study was to evaluate phonemic and semantic lexical access abilities in adults with bilateral severe to profound hearing loss and then to re-evaluate a cohort after cochlear implantation. 103 adult subjects underwent phonemic and semantic fluency tests during a cochlear implant candidacy evaluation. Of the total 103 subjects, 43 subjects underwent the same tests at 3 months post-implantation. Our results showed superior performance in phonemic fluency compared to semantic fluency in subjects prior to implantation. Phonemic fluency was positively correlated with semantic fluency. Similarly, individuals with congenital deafness had better semantic lexical access than individuals with acquired deafness. Results at 3 months post-implantation showed an improvement in phonemic fluency. No correlation was found between the evolution of pre- and post-implant fluency and the auditory gain of the cochlear implant, and we found no significant difference between congenital and acquired deafness. Our study shows an improvement in global cognitive function after cochlear implantation without differentiation of the phonemic-semantic pathway. Approximately 25% of French adults are affected by hearing loss, of which 4% are at a disabling level . A weak At the cognitive level, cochlear implantation leads to improved performance in attention, memory ,13 and iVerbal fluency tests are regularly used to assess lexical access ,16. TheySemantic and phonemic fluencies depend on distinct neural systems. For phonemic verbal fluency, it can be seen with Functional Magnetic Resonance Imagining (fMRI) that the posterior regions of the left inferior frontal gyrus are more activated. On the other hand, for semantic fluency there is greater activation of the more anterior regions of the frontal and posterior regions of the temporal cortex ,19.Adults with severe to profound post-lingual hearing loss have a deterioration of phonological memory and its dorsal  pathway. The longer the subjects are exposed to this hearing loss, the more they use the ventral semantic  pathway to compensate for the lack of elementary phonological decomposition . PhonoloThese difficulties with internal phonological representations and the degradation of auditory information worsen with the duration of auditory deprivation . For posThis study aims, firstly, to establish the phonemic and semantic lexical access abilities of adult subjects with bilateral severe to profound hearing loss and, secondly, to evaluate the impact of the cochlear implantation on phonemic and semantic lexical access.n = 83), congenital hearing loss (n = 20). The etiologies are described in One hundred and three subjects participated in the present study (N = 103). The group consisted of 43 males and 55 females . 15 subjects had primary school education, 36 subjects had secondary school education, and 49 had higher education. Data on education level was missing for 3 subjects. The origin of the hearing loss was variable: acquired hearing loss  AVIS number 2020-62. All participants signed an informed consent form before the start of the study.We used Cardebat’s fluencies  to assesp < 0.05 .The Z-score was calculated using Cardebat’s fluency calibration . This caOf the 103 participants, 2 individuals were below the pathology threshold (Z = −2) in phonemic fluency and 6 individuals in semantic fluency. p-value shows that this result is significant (p = 0.043 *). In addition, there is a significant positive correlation between the phonemic fluency Z-score and the semantic fluency Z-score . The mean Z-score for phonemic fluency is higher than that for semantic fluency. The The results of the phonemic and semantic fluency Z-scores according to the origin of the participants’ deafness  are described in p-value is significant for the Z-score in semantic fluency (p = 0.043 *). The p-value is not significant for the phonemic fluency Z-score.The results show higher Z-scores in phonemic and semantic fluency for participants with congenital deafness. The n = 31), congenital hearing loss (n = 12). The etiologies were diverse: 11 subjects had presbycusis, 5 subjects had congenital bilateral profound hearing loss, 3 subjects had otosclerosis-related hearing loss, 3 subjects had genetic hearing loss, 2 subjects had Pendred’s syndrome, 2 subjects had Meniere’s disease, 2 subjects had Meniere’s disease associated with chronic otitis, 2 subjects had hearing loss due to inner ear malformations, and 2 subjects had congenital deafness with abrupt worsening. 11 subjects had other etiologies: fragile X syndrome, autoimmune, idiopathic, meningitis, chronic ear infections, ototoxicity, sepsis.The subjects included in study 2 (N = 43) were from study 1. The group consisted of 19 males and 24 females . 4 subjects (9%) had primary school education, 13 (30%) subjects had secondary school education and 25 (58%) had higher education. Data on the educational level of 1 (2%) subject was missing. The origin of the hearing loss was variable: acquired hearing loss , Cochlear (n = 16), Advanced Bionics (n = 7) and Oticon Medical (n = 7).Different brands of cochlear implants were used: Medel .The Z-score was calculated following the fluency calibration of Cardebat . This caOf the 43 subjects, one subject was below the pathological threshold (Z = −2) in phonemic fluency post cochlear implantation. For semantic fluency, 2 subjects were below the pathological threshold pre- and post-cochlear implantation. One participant went from a non-pathological to a pathological Z-score after implantation. One participant went from a pathological to a non-pathological Z-score after implantation.p-value shows that the result is significant (p = 0.024 *). In semantic fluency, the post-implantation Z-score is slightly higher than the pre-implantation Z-score, but this value is not significant (p = 0.863).The results show a higher Z-score for post-implantation phonemic fluency than for pre-implantation phonemic fluency. The The differences in phonemic fluency Z-scores post implant and pre implant show a gain for both groups. The mean is higher in the group of subjects with acquired hearing loss than in the group with congenital hearing loss.p = 0.751 and p = 0.692).The difference in semantic fluency Z-scores post implant and pre implant shows a small gain for the group of subjects with an acquired hearing loss. For subjects with congenital hearing loss the difference in semantic fluency Z-scores post implantation and pre cochlear implantation shows a small loss. No significant difference was found between the two groups in the post-implantation condition in either fluency .The results show no correlation between pre-implantation phonemic and semantic Z-score differences and implant gain  semantic pathway .Secondly, we assessed the impact of cochlear implantation on phonemic and semantic lexical access. Study 2 showed a positive impact of the cochlear implant on phonemic fluency as early as 3 months post implant. Thus, cochlear implantation allowed for better phonological representation and better access to the dorsal pathway. This benefit of the cochlear implant appears relatively early after surgery. These results are important because most studies have highlighted cognitive changes at six months or one year but not so early. Indeed, since ten years the clinical research on the cognitive improvement by cochlear implantation has become increasingly recognized. Especially, studies have showed improvements in different cognitive functions as processing speed, cognitive flexibility and working memory ,29,30. TStudy 2 showed no significant difference in pre- and post-cochlear implantation fluency between groups based on the origin of the hearing loss. The contribution of the cochlear implant on phonemic and semantic fluency is as effective for an acquired hearing loss as for a congenital one at 3 months post-implant. No correlation was found between differences in post- and pre-implant fluency and implant auditory gain. At 3 months post-implantation, the benefit of the cochlear implant is not specific to the phonemic and semantic pathways. The distribution between the pathways is not determined.Finally, the improvement in participants verbal fluency, even elderly, and this very quickly, adds proof of the interest of cochlear implantation for cognitive stimulation and the prevention of cognitive decline as suggested by other studies .It would be interesting to continue this study with a longer post cochlear implantation observation time to see if a correlation could be obtained between implant gain and the difference in phonemic and semantic fluency. It might also be interesting to analyse clustering  and switching (moving from one subcategory to another) in verbal fluency tasks in people with hearing impairment.A major limitation of our study is the short post-implantation interval. We observed verbal fluency only 3 months after implantation whereas most studies analyse cognition 1 year after implantation. Indeed, activation of the auditory associative cortex continues to increase even years after cochlear implantation for stimuli containing speech . AnotherOur study showed higher phonemic fluency than semantic fluency, in contrast to previous studies. At 3 months after surgery, we observed a benefit of the cochlear implant in adults without differentiation between the phonemic and semantic pathways and regardless of the origin of the hearing loss. This study could be continued over a longer period of observation post cochlear implantation. It might be relevant to compare the impairment of phonemic and semantic pathways with that of executive functions in adults with hearing impairment.


Cordyceps militaris is widely exploited in traditional medicine and nutraceuticals in Asian countries. However, fruiting body production in C. militaris is facing degeneration through cultivation batches, and the molecular mechanism of this phenomenon remains unclear. This study showed that fruiting body formation in three different C. militaris strains, namely G12, B12, and HQ1, severely declined after three successive culturing generations using the spore isolation method. PCR analyses revealed that these strains exist as heterokaryons and possess both the mating-type loci, MAT1-1 and MAT1-2. Further, monokaryotic isolates carrying MAT1-1 or MAT1-2 were successfully separated from the fruiting bodies of all three heterokaryotic strains. A spore combination of the MAT1-1 monokaryotic isolate and the MAT1-2 monokaryotic isolate promoted fruiting body formation, while the single monokaryotic isolates could not do that themselves. Notably, we found that changes in ratios of the MAT1-2 spores strongly influenced fruiting body formation in these strains. When the ratios of the MAT1-2 spores increased to more than 15 times compared to the MAT1-1 spores, the fruiting body formation decreased sharply. In contrast, when MAT1-1 spores were increased proportionally, fruiting body formation was only slightly reduced. Our study also proposes a new solution to mitigate the degeneration in the heterokaryotic C. militaris strains caused by successive culturing generations.The medicinal mushroom  Cordyceps species are entomopathogenic ascomycete fungi. The Cordyceps genus comprises over 400 species that mainly parasitize in arthropods. Many species of this fungal genus are able to produce abundant bioactive substances with beneficial effects on human health [Cordyceps species, Cordyceps militaris is cultivated artificially at a large scale for fruiting bodies. Fruiting bodies of C. militaris contain valuable bioactive ingredients such as cordycepin, adenosine, pentostatin, polysaccharides, and digestive enzymes. Therefore, sexual fruiting bodies of this fungus have been widely consumed as edible and medicinal ingredients in Asian countries, including Vietnam [n health ,2,3,4. A Vietnam ,6,7,8.C. militaris is a heterothallic fungus whose sexual reproduction to form fruiting bodies requires both opposite mating-type partners, MAT1-1 and MAT1-2. A heterokaryotic strain (a dikaryon/diploid) harbors both MAT1-1 and MAT1-2 nuclei, and single-ascospore isolation can help to obtain haploidic MAT1-1 and MAT1-2 isolates (monokaryons/haploids) from the parental heterokaryotic strain [MAT1-1 and MAT1-2 loci contain transcription factor genes required for mating and sexual development. Structural analysis of these mating-type loci in C. militaris revealed that the MAT1-1 locus contains the MAT1-1-1 and MAT1-1-2 genes, while the MAT1-2 locus carries only the MAT1-2-1 gene. The accurate functioning of this mating system results in the formation of complete fruiting bodies as perithecial stromata [MAT1-1 or MAT1-2 resulted in impairment of the fruiting body formation in C. militaris [MAT1-1 mating-type strains of C. militaris, Cordyceps takaomontana, and Cordyceps cardinalis can also form fruiting bodies, but these stromata are sterile, without perithecia or ascospores [c strain ,10. The stromata ,11. Deleilitaris . Strikincospores ,13. The C. militaris is characterized by the reduction in fruiting body formation, mycelial growth rate, pigmentation, and production of bioactive metabolites [C. militaris is complex and remains unclear. It may involve environmental factors, genetic variations, and changes in gene expression [C. militaris strains, including G12, B12, and HQ1, degenerated after three consecutive culturing generations by using the spore isolation method and effects of the MAT1-2 mating-type spores on the degeneration of fruiting body formation in these strains.Successive subculturing of mycelia or spores for several generations in filamentous fungi and mushrooms causes degeneration ,16,17,18abolites ,20. Degeabolites ,22,23. Hpression ,23,24. IC. militaris strains, namely G12, H8, M5, B12, and HQ1, were provided by the National Key Laboratory of Enzyme and Protein Technology, University of Science, Vietnam National University, Hanoi. These strains were preserved in 20% glycerol at 4 °C.Five The potato dextrose broth (PDB) medium comprised the infusion broth with 200 g peeled potato, 20 g glucose, and distilled water to 1000 mL. To this medium, 2% agar was added, and it was named potato dextrose agar (PDA).C. militaris strains. This medium, including 28 g brown rice and 60 mL of a nutrient solution, was added to a 600 mL round transparent plastic box for fungal inoculation. The nutrient solution comprised the infusion broth from 200 g peeled potato, 15 g glucose, 15 g sucrose, 1 g MgSO4, 1 g KH2PO4, 1 g peptone, 100 g finely ground silkworm pupae biomass, and distilled water to 1000 mL.Brown rice (BR) medium was used for the fruiting body formation of All media were autoclaved at 121 °C for 20 min before use.C. militaris strain was mounted on the inside lid of a Petri dish with sterile sticky tape as previously reported [6 spores/mL and stored at 4 °C for further experiments.A single fruiting body of each heterokaryotic reported . The PetC. militaris strains  were chopped and used directly as the starting material for DNA extraction. Total DNA was also extracted from fungal mycelium prepared: one milliliter of the spore suspension (106 spores/mL) was added to a 100 mL Erlenmeyer flask containing 50 mL of the PDB medium. The flask was incubated in an orbital shaker at 200 rpm and 25 °C for 3 days. The culture was filtered through Miracloth to collect fungal mycelial biomass.Fruiting body samples obtained from the artificial cultivation of five Total DNA extraction was adapted from our previous work with slight adjustments . BrieflyC. militaris strains were used for PCR to detect the mating-type genes MAT1-1-1 (for the MAT1-1 locus) and MAT1-2-1 (for the MAT1-2 locus). PCR amplifications involved GoTaq® Green Master Mix  and two specific primer pairs, MAT1-1-1-F (5′-ATGGAACACAGATCGAGCGACAC-3′)/MAT1-1-1-R (5′-ATATACCTTCGCGATCATT GCCCAG-3′) and MAT1-2-1-F (5′-TGTTTTGTCGCGATGGTTCTGG-3′)/MAT1-2-1-R (5′-CCTCTGGAGGTTCTGCATTCCA-3′) [Total DNA samples extracted from fungal materials of the TCCA-3′) . The steC. militaris strains were consecutively grown on the PDA medium for five generations. First, an original strain was cultivated on a PDA plate to collect new spores (1st generation). Next, the harvested spores were grown to harvest new spores (2nd generation). This cycle was repeated to have the next generations . All five generations of each C. militaris strain were used to evaluate the fruiting body formation ability. One milliliter of a spore suspension (106 spores/mL) from each generation was inoculated into a flask containing the PDB medium supplemented with 0.1% peptone . The flask was kept in a shaking incubator at 200 rpm and 25 °C in the dark for 3 days. A volume of 3 mL of the culture was spread evenly onto the surface of the brown rice (BR) medium in a 600 mL round transparent plastic box . After the inoculation, the box was incubated at 25 °C in the dark for 7 days to promote the colonization of fungal mycelium to the entire surface of the substrate. The box was transferred to culture conditions of a lighting cycle of 12 h under the light/12 h in the dark, a light intensity of 500–700 lux, a temperature of 22 °C, and a humidity of 85–90%. The box was maintained under these conditions for 45 days to promote fruiting body formation.Five MAT1-1 or MAT1-2 derived from the heterokaryotic C. militaris strains  were mixed in pairwise combinations to examine fruiting body formation. Spores from each MAT1-1 isolate and each MAT1-2 isolate were combined with different ratios: 1:1, 1:5, 1:10, 1:15, 1:20, 1:25, 1:30, 5:1, 10:1, 15:1, 20:1, 25:1, and 30:1. Each mixed spore ratio was added to a conical flask containing PDB medium and grown at 200 rpm and 25 °C for 3 days. Obtained cultures were inoculated to the BR medium to promote fruiting body formation as described above. Fruit bodies were harvested, and the parameters of height, weight, and number of fruit bodies from each culture box were documented for comparative analyses.Monokaryotic isolates carrying MAT1-1 and MAT1-2 monokaryotic isolates derived from the heterokaryotic C. militaris strains  were cultured separately on the PDA medium for five successive generations using the spore isolation method. For each generation, the MAT1-1 isolate was mixed with the MAT1-2 isolate at the 1:1 ratio and grown in the PDB medium supplemented with 0.1% peptone . The mixed culture was spread on the BR medium to promote fruiting body formation as described above. The effectiveness of fruiting body formation was evaluated through height, weight, and number of fruiting bodies per culture box.The p < 0.05.Data were expressed as means ± standard deviations and analyzed statistically using one-way analysis of variance (ANOVA). Analyses were performed with GraphPad Prism 8  using Tukey’s test. A statistical difference was considered when MAT1-1 and MAT1-2) in all five tested C. militaris strains  with PCR using the primers specific for the MAT1-1-1 and MAT1-2-1 genes. Results showed that strains H8 and M5 carried only the MAT1-1 mating-type locus, while G12, B12, and HQ1 were confirmed as heterokaryotic strains carrying both the mating-type loci, MAT1-1 and MAT1-2, in their genomes. Artificial cultivation of these C. militaris strains on the BR medium revealed that all five strains could form normal fruiting bodies  was strongly decreased  carrying only MAT1-1 without an opposite mating-type partner in its genome is still able to form fruiting bodies (stromata). However, these fruiting bodies are incomplete due to the lack of perithecia (the flask-shaped fruiting structure) and ascospores [MAT1-1 strains of C. takaomontana and C. cardinalis [MAT1-1 mating-type locus were more stable for fruiting body formation than heterokaryotic strains G12, B12, and HQ1 through successive culturing generations . Fungal colonies developed from ascospores were examined for the mating-type loci MAT1-1 and MAT1-2. PCR results showed that some colonies carried only a single mating-type locus as MAT1-1 or MAT1-2. However, we also found that many colonies still existed as heterokaryons carrying both MAT1-1 and MAT1-2. Perhaps it is difficult to separate single ascospores from each other by using the fruiting body mounting method.Using the fruiting body mounting method , we succMAT1-1) and G2 (MAT1-2) from strain G12, B5 (MAT1-1) and B6 (MAT1-2) from strain B12, and H3 (MAT1-1) and H2 (MAT1-2) from strain HQ1 (MAT1-1 or MAT1-2 monokaryotic isolates obtained from the hybrid C. militaris Cm06 strain on caterpillar pupae resulted in the formation of sterile fruiting bodies lacking perithecia and ascospores [MAT1-1 isolate and a MAT1-2 isolate was required to induce the fruiting body formation on the BR medium (C. militaris Cm09 strain [We selected six colonies as monokaryotic (haploid) isolates derived from the heterokaryotic strains  for fruiting body formation assays. These monokaryotic isolates included G4  [Sung et al. (2006) inspected the effect of different ratios of two mono-ascospore strains in pairwise combinations on fruiting body formation in  and 4:1 . Later, tromata) . Based oMAT1-1 × MAT1-2) at the spore ratios of 1:1, 1:5, 1:10, 5:1, 10:1, 15:1, 20:1, 25:1, and 30:1. However, it was astonishing that the formation of fruiting bodies strongly declined in the combinations at the ratios of 1:15, 1:20, 1:25, and 1:30. These results revealed that an excessive increase in the MAT1-2 spores (over 15 times) compared to the MAT1-1 spores led to the degeneration in the heterokaryotic strains of C. militaris. In contrast, an excessive increase in the MAT1-1 spores (even 30 times) of the combination only caused a slight reduction in fruiting body formation  showed that the  showed t strains ,11. Howeneration . A recenC. militaris strains occurs after a few generations of successive subculturing, and the formation of fruiting bodies can even be lost entirely [MAT1-1 and MAT1-2 monokaryotic isolates for five consecutive generations using the spore isolation method. The monokaryotic isolates from each generation were then combined at a 1:1 spore ratio. Our results revealed that the formation of fruiting bodies in the hybrid strains was similarly maintained through all five generations  isolation. In contrast, the sterile fruiting body formation in the MAT1-1 monokaryotic strains was more stable through consecutive culturing generations. We also discovered that an excessive increase in the MAT1-2 spores of over 15 times compared with the MAT1-1 spores led to the degeneration of fruiting body formation in all three examined heterokaryotic C. militaris strains . To mitigate the degeneration in the heterokaryotic strains through culturing generations, their monokaryotic isolates should be separately kept before being combined for fruiting body production.This study showed that the sexual (fertile) fruiting body formation in the


This study evaluates intracochlear electrocochleography (ECochG) for real-time monitoring during cochlear implantation. One aim tested whether adjusting the recording electrode site would help differentiate between atraumatic and traumatic ECochG amplitude decrements. A second aim assessed whether associations between ECochG amplitude decrements and post-operative hearing loss were weaker when considering hearing sensitivity at the ECochG stimulus frequency compared to a broader frequency range. Eleven adult cochlear implant recipients who were candidates for electro-acoustic stimulation participated. Single-frequency (500-Hz) ECochG was performed during cochlear implantation; the amplitude of the first harmonic of the difference waveform was considered. Post-operative hearing preservation at 500 Hz ranged from 0 to 94%. The expected relationship between ECochG amplitude decrements and hearing preservation was observed, though the trend was not statistically significant, and predictions were grossly inaccurate for two participants. Associations did not improve when considering alternative recording sites or hearing sensitivity two octaves above the ECochG stimulus frequency. Intracochlear location of a moving recording electrode is a known confound to real-time interpretation of ECochG amplitude fluctuations, which was illustrated by the strength of the correlation with ECochG amplitude decrements. Multiple factors contribute to ECochG amplitude patterns and to hearing preservation; these results highlight the confounding influence of intracochlear recording electrode location on the ECochG. Reducing intracochlear trauma during cochlear implantation is desirable not only to optimize acoustic hearing preservation but also to maximize the general benefit from electrical stimulation ,2,3. SurElectrocochleography is well suited for monitoring intracochlear trauma from electrode array insertion because the contributing physiological generators are peripheral, including cochlear hair cells (inner and outer) and auditory afferent fibers. Components of the composite ECochG include onset/offset responses , an ongoing, sustained response , and an ongoing, frequency-following response . Sensitivity of the ECochG response to cochlear trauma has been directly observed in animals when blunt force impact has been intentional, and injury to the osseous spiral lamina, basilar membrane, or spiral ligament is confirmed by histology ,19,20. AIn humans, careful measures are taken to avoid traumatic injury to residual elements of the inner ear during cochlear implantation. Even so, hearing loss shortly after the surgery ranging from partial to complete implies traumatic events of varying degrees . DespiteAlthough interest in intraoperative ECochG monitoring for optimizing electrode placement remains high, it is also clear that current approaches complicate real-time interpretation. A primary example is the confound introduced by using the electrode array for recording the ECochG. An intracochlear recording site is desirable because it generally measures a substantially larger signal compared to an extracochlear (often round window) recording site ,29,30. ADespite the proximity to the response generators that an intracochlear electrode affords, it is important to remember that the ECochG is a field potential, and the amplitude is the integration of all contributing generators, weighted by nearness and orientation to the recording site. Generator contributions are controlled by the amplitude and phase of basilar membrane/tectorial membrane displacement, which has both excitatory and inhibitory motion occurring simultaneously across its length . SpecifiIncorporating other metrics derived from the ECochG to consider along with amplitude decrements has been proposed to help differentiate which decrements reflect trauma from ones that do not. Adding the rate of amplitude change to the size of the amplitude decrement improves predictions ; howeverWhile many of these approaches are promising, they are not yet available with manufacturer systems or are not available to be used in real time as feedback. Evoking the ECochG using multiple frequencies and comparing associated response patterns is currently feasible ,25,38,39The purpose of this study was to further investigate the real-time interpretation of single-frequency ECochG amplitude decrements during electrode array insertion. The overarching goal was to evaluate whether ECochG amplitude patterns were predictive of post-operative hearing loss in a setting where feedback was available to the surgeon. The first aim was to explore whether a monitoring strategy that included the opportunity to adjust the recording electrode in real time would improve interpretation of an amplitude decrement. It was hypothesized that recording similarly diminished amplitudes at a more basal site would confirm results at the more apical site, indicating trauma, while recording larger amplitudes at a more basal site would signify better hearing preservation outcomes than predicted by the apical recording. Giardina and colleagues  suggesteThe second aim considered whether the single-frequency ECochG would be most predictive of hearing sensitivity in the same frequency region or across a broader frequency range. Traveling-wave patterns initiated by suprathreshold, low-frequency tone-burst stimuli used to evoke the ECochG are broader than traveling-wave patterns initiated by threshold-level, low-frequency tonal stimuli used to assess hearing sensitivity. It was hypothesized that correlations between ECochG amplitude patterns and hearing preservation would be stronger when considering hearing sensitivity across a range of frequencies  compared to hearing sensitivity matched to the ECochG stimulus frequency due to basilar membrane displacement in the basal tail of the traveling wave.Finally, the results were also used to further illustrate the confounding impact of the intracochlear location of the recording electrode on ECochG amplitude decrements. It was predicted that unanticipated hearing preservation outcomes would be observed in cases for which the tonotopic frequency associated with the intracochlear location of the apical recording electrode is nearer to the ECochG stimulus frequency.All procedures were performed in accordance with ethical standards for human research and approved by the University of Iowa Hospitals and Clinics (UIHC) Institutional Review Board (IRB 201805740 or 202210440). Informed consent was obtained from all subjects involved in the study.Adult patients at UIHC who were deemed CI candidates, who met Med-El electric-acoustic stimulation (EAS) candidacy criteria  imaging has become a standard component of the CI evaluation and follow-up process at this institution. A subset of scans was photon-counting. OTOPLAN V.02 or V.03 software  was used for cochlear measurements and parameter estimates see . Pre-opeThe “electrode visualization” feature of the OTOPLAN software combines cochlear duct length estimates from the pre-operative CT scan with projected intracochlear electrode array lengths to provide individualized estimates of insertion angle and associated tonotopic frequency. Frequency estimates calculated from the organ of Corti map were preferred over the spiral ganglion map because the electrode array was being used as a recording instrument (rather than as a stimulation device) and because hair cells contribute to the acoustically evoked ECochG. Tonotopic frequency estimates combined with pre-operative audiometric profiles were used to guide the choice of electrode array length  and insertion depth for each participant see . The estEstimates of electrode insertion depth and tonotopic frequency were updated using post-operative CT images, which captured the array in its actual/final intracochlear position. Post-operative scans were also used to assess the presence of scalar translocations and extracochlear electrodes. Post-operative scans were available for all participants.TM; iotaMotion Inc, Iowa City, IA, USA). Robotic electrode array insertion is slower, steadier, and more controlled compared to manual insertion [TM tool was utilized compared to manual insertions [Cochlear implantation was performed by one of three neurotologists using a conventional postauricular approach. The round window was accessed via the facial recess following a standard mastoidectomy. Dexamethasone was applied topically prior to opening the round window. The array was inserted via the round-window opening using a robotics-assisted insertion tool  that controlled a MAX programming interface (reverse telemetry system to utilize the electrode array for recording) and a Dataman 531 waveform generator (acoustic stimulator). The Dataman receives a trigger from the MAX programming interface for synchronized stimulation/recording. Acoustic stimuli were routed to an ER-3C 50-Ω insert earphone with a 25-cm tube. A dome ear tip coupled to the insert earphone was placed in the ear canal of the ear to be implanted and secured prior to sterilization.Intraoperative measurements were initiated after the surgeon reported intracochlear placement of at least one electrode. Insertion was paused to allow for an electrode impedance measurement, followed by the presentation of an electrical conditioning stimulus (500 cu) on electrodes 1 and 2 to potentially improve the intracochlear recording by further lowering the impedance. The acoustic stimulus used to elicit the ECochG was a 500-Hz tone burst (8 ms) presented with alternating polarity at 105 dB HL. The recording window was 9.6 ms. The most apical electrode (e1) was selected initially for recording.The software performed repeated fast Fourier transforms on the difference waveform (mean of 100 sweeps). Amplitudes of the first and second harmonics  were updated every 20 or 10 sweeps . A software version change after the first three participants was responsible for the change in the number of sweeps/update speed. In the most current version, an updated amplitude estimate was available for review approximately every 1.6 s. Two examples are provided in An audiologist reported the response amplitude and described the trajectory  in real time. References to the maximum were frequently provided for context. The surgeon integrated the feedback with multiple sources of information about the case to influence decisions such as pausing or reversing insertion or adjusting trajectory. Partial insertions were sometimes planned prior to the surgery; ECochG amplitudes could also be used to influence insertion-depth decisions.A strategy was adopted to adjust the recording electrode if an amplitude decrement was observed. In the event of a decrement, insertion was often paused, or the electrode was slightly withdrawn to allow the recorded amplitude to stabilize. If the surgeon’s adjustments did not result in a recovered response amplitude, a new ECochG measurement was initiated with an adjacent, more basally located electrode (e2). Use of the robotic insertion system facilitated this approach, as the array remains completely stable when insertion is paused. If the ECochG amplitude was larger in the new measurement than the final amplitude in the previous recording, electrode array insertion and ECochG monitoring continued. If the same or smaller amplitude was observed at the beginning of the measurement, the next adjacent electrode in the basal direction could be tested as a recording site (e3). If an amplitude decrement was observed with the adjusted recording site, a decision could be made to switch back to e2 or e1. Time constraints limited the number of recording electrodes for any given case. If the recording electrode was adjusted during array insertion, a repeated measurement with e1 as the recording site was performed once the electrode array was in the final position.The “final ECochG amplitude” was the last measurement that was obtained once the electrode array was in the final position (after packing around the round window and securing the lead). If the recording site had been adjusted, then a second “final” amplitude was calculated from a repeated measurement with e1. The final amplitude(s) were normalized to the maximum to quantify the global response pattern as a proportion and to facilitate comparisons across ears.Behavioral pure-tone thresholds were used to characterize hearing sensitivity. Unaided post-operative audiometric thresholds were assessed at the initial activation appointment approximately 1-month post-operatively. These values were compared to pre-operative thresholds. If there was evidence of conductive overlay, post-operative thresholds were taken from a later time point after resolution of the conductive component. Because the ECochG monitoring stimulus was 500 Hz, preservation of hearing at 500 Hz was of interest as the matched frequency reference point. Changes in post-operative hearing relative to pre-operative hearing were quantified as percentages (modeled after Skarzynski and colleagues ):(1 − [ΘThe ECochG stimulus level was suprathreshold (105 dB HL) to increase the likelihood of a sufficient response amplitude for monitoring. Due to basal spread of basilar membrane excitation, hearing sensitivity in the two-octave range above 500 Hz was also considered. Equation (1) was adapted using the frequency-specific audiometric thresholds and audiometer limits. Two hearing preservation values at 2000 Hz were greater than 100% . Upon further examination, these values came from situations where pre-operative hearing was near the audiometric limits and post-operative thresholds were better than pre-operative thresholds (but still within test-retest reliability ranges). Hearing preservation values were replaced with 100% in these cases to avoid artificially skewing the data.p < 0.05.ECochG amplitude patterns were quantified as the final amplitude relative to the maximum. Simple linear regression was used to test predictions of hearing preservation from final ECochG amplitude. There was no evidence that regression assumptions were violated upon examination of residuals. A linear mixed model addressed the dependency of the prediction on audiometric threshold frequency. Pre- and post-operative CT scans were evaluated against ECochG amplitude using the Spearman correlation. Statistical significance is considered Insertion depth was also expected to vary across the electrode arrays with lengths of 20, 24, or 26 mm. Although shallower projected positions (and higher corresponding tonotopic frequencies) tended to be observed with shorter arrays, projected insertion depths from the pre-operative CT overlapped for the Flex 24 and 26 arrays, which illustrates the impact of cochlear size and the value of individualizing array choice. The pre-operative estimates identified two individuals (OP-04 and OP-09) for whom the projected tonotopic frequency corresponding to the place of the most apical electrode was lower than 500 Hz (the ECochG stimulus frequency). The highest pre-operative projected estimate was 1055.8 Hz for a recipient of a Flex 20 array.All tonotopic estimates from the post-operative CT images for e1 are higher than the pre-operative estimates, which is largely explained by the number of partial insertions  in 2 value decreased from 0.36 to 0.02, further demonstrating that the recording electrode strategy did not improve predictions  indicates that the relationship between ECochG amplitude decrements and hearing preservation does not vary by frequency. Neither the main effect of frequency nor ECochG amplitude decrements was statistically significant . These results suggest that hearing preservation predictions do not improve by considering hearing sensitivity at frequencies higher than 500 Hz compared to predictions focusing on 500 Hz.To evaluate the impact of higher frequencies on hearing preservation, we implemented a linear mixed model with fixed effects of frequency  and ECochG amplitude decrements, as well as the interaction. The interaction was the primary comparison of interest. A random intercept for the participant was included to account for repeated measures across frequency. The intraclass correlation was 0.71, indicating substantial correlation of hearing preservation between frequencies. The interaction  although not statistically significant when considering pre-operative estimates, but it was significant with a high correlation (r = 0.85) when using the position estimated from the post-operative scan. This correlation is stronger than the relationship between ECochG amplitude and hearing preservation outcomes . Of partThis study expands upon previous investigations of ECochG for real-time monitoring by (1) evaluating whether adjusting the recording electrode would improve predictions of post-operative hearing loss from the ECochG amplitude decrements; (2) considering hearing sensitivity at frequencies higher than the ECochG stimulus frequency; and (3) illustrating the confounding effect of the intracochlear electrode position on the interpretation of single-frequency ECochG amplitude decrements. Neither adjusting the recording electrode nor including behavioral thresholds at 1000 and 2000 Hz improved predictions of post-operative hearing sensitivity. The intracochlear position of the recording electrode was more strongly correlated with ECochG amplitude decrements than the correlation between ECochG amplitude and post-operative hearing preservation.Selecting adjacent electrodes in succession was anticipated to be a sufficient recording site adjustment given the length of the Flex 24 and 26 arrays and spacing across electrodes . Although maximal ECochG responses evoked with a 500-Hz stimulus have been recorded up to six electrodes away from the most apical site for modiolar-hugging arrays, the maximum response has been observed primarily at the apical electrode for lateral wall arrays . A singlGiven the high stimulus level and low frequency used to elicit the ECochG, it was of interest to determine whether amplitude decrements would better predict hearing sensitivity when including frequencies higher than the ECochG stimulus. This prediction was based on the general notion that the traveling wave broadens with stimulus intensity, and the peak shifts to a more basal site . This meIn the present investigation, including audiometric thresholds at 1000 and 2000 Hz (one and two octaves above the ECochG stimulus) in the hearing preservation calculation did not improve predictions from the ECochG . A complA relationship between recording electrode insertion depth and ECochG amplitude decrement was anticipated given that ECochG maxima are more frequently measured at basal electrodes for arrays with deeper insertion angles . This stIn this data set, ECochG amplitude decrements were smallest for electrodes that terminated between the 1000 and 2000 Hz tonotopic place, or approximately 3 mm basal to the expected tonotopic site for 500 Hz. Though this finding is a cross-subject observation, it is generally consistent with the post-operative measurements performed across multiple electrodes for a given individual: the recording electrode with the maximum amplitude tends to be more basal than anticipated from the tonotopic map ,50. ThisNone of the apical electrodes crossed the 500 Hz place, largely because of the number of partial insertions, and yet ECochG amplitude declined to 10–22% of the maximum in four cases. An explanation that has become popular to describe an atraumatic amplitude decrement is the advancement of the recording electrode past the generation site. The tonotopic site of maximal sensitivity was not passed by the apical electrode in any of the cases included in this report. OP-04 specifically is an example of an atraumatic decrement. These results suggest that atraumatic amplitude decrements can be observed even for electrodes that terminate basal to the tonotopic place of the ECochG stimulus.The number of partial insertions in this data set was high (7 of 11 participants). The shallowest insertion was 267.6°, which is similar to the average insertion depth for a L24 array , but alsFew studies have investigated the provision of real-time feedback on hearing-preservation outcomes. Harris and colleagues  used an The slow speed at which physiological information is updated limits the effectiveness of potentially corrective actions. In this study, the real-time ECochG analysis updated every 1.6 sec with an amplitude that was the moving average of previous sweeps (though weighted to most recent sweeps). Although some systems have automated alerts, this study used an audiologist to relay information to the surgical team. The processing speed and communication decisions of the intermediary further delayed the transmission of information. In this investigation, the slow provision of feedback was partially mitigated by the use of the robot that controlled electrode array insertion speeds at a slower rate than can be achieved manually and that could be stopped in a stabilized state at any moment. An insertion device that integrates ECochG directly would be reduce the time delay between an electrophysiological change and a reaction, likely improving the effectiveness of surgical modification .This study simplified the ECochG amplitude pattern by focusing on the final amplitude relative to the maximum. In some instances, multiple decrements were observed. For example, a decrement occurred in the middle of insertion for OP-01 and resolved by the end of insertion. By focusing on final amplitude, decrements such as these were not captured but are likely relevant when considering the risk of intracochlear trauma across the entire procedure .This study was also limited to a single metric: the amplitude decrement of the ECochG evoked with a single frequency. Numerous analytical opportunities exist with the ECochG, and the ideal metric for real-time monitoring is likely a combination of several measures ,36,37,38Due to the small sample size, the analyses reported within this manuscript were necessarily limited. Multiple factors contribute both to ECochG response amplitude patterns and to hearing preservation, and these factors likely co-vary. For example, pre-operative hearing was better for shorter arrays than longer arrays in this sample; shorter arrays were associated with shallower insertion depths, larger ECochG amplitudes, and better hearing preservation post-operatively. It is uncertain which factors are causative and which are the consequence, or how they interact. More work is needed with larger samples to better understand the contributions of the multiple factors.Because CI recipients, especially those considered for electro-acoustic stimulation management, tend to have limited residual hearing at high frequencies, ECochG monitoring is often restricted to low frequencies. The likelihood of atraumatic ECochG amplitude fluctuations increases as the recording electrode advances. The risk of intracochlear trauma also increases with insertion depth . It is c


The WHO emphasizes lifelong management of hearing diseases such as hearing loss and advocates for prevention. The Ear and Hearing Care Situation Analysis (EHCSA) tool was designed by the WHO for assessment and quality improvement of state-led management of hearing loss prevention and management programs. The purpose of this study was to use the EHCSA to assess the ear and hearing management program in Korea and to establish goals consistent with best practices for improving policies and services related to ear and hearing care.The EHCSA was used as a need assessment of the ear and hearing management services in the country. The EHCSA consists of two sections. Section 1 consists of 41 questions to evaluate health policies and support services. Section 2 consists of 203 questions to evaluate human resources and services of the ear and hearing management sector.There are an estimated 800,000 people with hearing loss in Korea. Policies such as hearing aid support are in place, and outreach services such as free hearing tests are also being actively conducted. In all medical institutions, ear and hearing management treatment and medication prescriptions could be received without barriers. Workers in the fields of ear and hearing management, such as audiologists, language therapists, special education teachers, and sign language interpreters, are specialized and have well-established guidelines for training.Overall, the domestic ear and hearing management sector has confirmed that policies and services are well-prepared in comparison with advanced countries such as the United States, Iran, and China. The use of the EHCSA was functional in collecting data on the current state of domestic ear and hearing management policies and services in Korea, can be used for continuous quality improvement and expansion of medical services, and can be used as a reporting mechanism to the WHO. Hearing is one of the five senses and refers to a mechanical sense that detects the frequency and intensity of sound waves transmitted through a medium, such as air or water. The ear is a sensory organ that causes brain activity, which leads to thoughts and emotions, and it has a proportion equivalent to vision in perceiving the surrounding environment . By 2050Accordingly, since 2005, China has been implementing a national project called the Hearing the Future-China National Hearing Care Program, which includes the early diagnosis, prevention, treatment, and rehabilitation of hearing loss. India has also continued to implement a state-led policy called NPPCD since 2008, and Australia is operating a government-led program to manage and supervise hearing screening, diagnosis, hearing loss prevention, and rehabilitation services from newborns to the older adult. The United States is striving to reduce the occurrence of social problems caused by hearing loss through the national “Healthy People 2020”  is a method for situation analysis developed by the WHO and includes the conditions of situation analysis . SituatiThe “WHO EHCSA” was distributed to collect, evaluate, and report on ear and hearing management policies, services, and human resources and for the assessment of national health systems in the context of ear and hearing management. This can help to understand the dynamics of hearing loss and the systems and policies that support ear and hearing management, including available personnel, infrastructure, and services, and to establish an improved healthcare system that can help with hearing management. The tool has a total of two sections: Section 1 and Section 2 with a total of 41 and 203 questions, respectively. Section 1 provides information on overall health policies and services, such as total population, age distribution, gender distribution, illiteracy rate, Internet penetration rate, life expectancy, fertility rate, vaccination status, deaf patient distribution, infant health policy, youth health policy, and disease management protocol. Section 2 provides detailed information on human resources, such as departments and representatives dealing with ear and hearing care issues in the Ministry of Health and Welfare, ear and hearing care-related institutions, policies, and programs. Questionnaires for assessment are also available .The emphasis was on collecting indicators in line with the context of the questions in the WHO ear and hearing care situation analysis tool. Information, such as country profiles and holidays, was collected using documents from national institutions, such as WHO statistics, the Ministry of Health and Welfare, and the National Statistical Office. First, the indicators of the National Statistical Portal (KOSIS) serviced by the National Statistical Office were confirmed. In addition, to confirm the specific information, documents, such as project reports and academic publications of national institutions that calculated the indicators, were checked. Finally, if the index was not secured through the search, consultations were conducted with experts.To answer the questions, open materials distributed by the state and materials from the conference were used. Data from the National Statistical Office, 2021 population and housing census, 2021 future population estimation, 2020 death cause statistics, and 2017 and 2021 birth statistics press releases were used. In the data from the Korea Centers for Disease Control and Prevention, the 2021 tuberculosis patient report status, 2020 HIV/AIDS report status year, and tuberculosis treatment guidelines were used. In the data from the Ministry of Health and Welfare, clinical guidelines for screening genetic testing for newborns, criteria for determining the grade of disablement, disaster crisis management measures for infectious diseases, and the classification of medical institutions were used. In addition, the World Population Review's literacy rate by the country in 2022, the Ministry of Science and ICTs 2021 wireless communication service subscriber statistics, the 2021 Internet usage survey, the Ministry of Education's school health inspection guidelines and integrated education guidebook, the National Health Insurance Service and Health Insurance Review and Assessment Service's health insurance statistics year, and hospital inquiry services were included. To use data from National Health Insurance, approval of the institutional review board is required. This study was approved by the Institutional Review Board of Yonsei University Wonju Severance Christian Hospital  (CR323326). The National Statistical Portal (KOSIS) provided by the National Statistical Office, Population and Housing Survey, and Disability Statistical Yearbook published by the Korea Disabled Development Institute were mainly used.The Korean Statistical Information Service (KOSIS) is a statistical service provided by the National Statistical Office for users to find the statistics they want at once by collecting major domestic and international statistics. Currently, it contains more than 1,000 types of state-approved statistics on the economy, society, and environment prepared by more than 300 institutions and provides the latest statistics on international finance, the IMF, the World Bank, and the OECD. Most national distribution data, such as the population and housing census and disability statistical yearbook, are uploaded on the portal .The population and housing general survey is a basic national statistical survey conducted by the National Statistical Office to understand the size and characteristics of all people and houses in Korea and is released annually. It is a national basic statistical survey conducted on people and residences in the national territory at a certain time and period and is used as basic data in various fields, including policymaking, planning, research, and evaluation by national institutions, private companies, academic organizations, and the public. It is used to prepare secondary processing statistics, such as the Ministry of Employment and Labor's labor supply plan, the Ministry of Health and Welfare's premium rate and national pension fiscal estimate, the low birth rate and aging index, and the Ministry of Land, Infrastructure, and Transport's housing supply rate . The disThe main priority was whether the criteria for determining the data were calculated by national ministries. As most of the data produced by national ministries are targeted at the entire nation and collected at the national level, it can be inferred that these data have been verified in terms of representation and reliability. If there were no data, the data of the academic society or association in the field were used; if there were no data in the institution, the engineer or expert was consulted. The year of the data to be used was set as 2021, as the data from the major national ministries for the year 2022 would be distributed the following year, and the most recent data were used if there were no data for the year 2021.The results of the population profile are shown in The results of the sociopolitical profile are shown in The results of the health status indicators are shown in The results of the hearing loss are shown in The results of the healthcare strategies are shown in The results of the EHC policies implemented by the Ministry of Health and Welfare and other institutions are shown in The results of the existence of primary medical care and the presence or absence of EHC are shown in The results of the overall state of the primary medical institutions are shown in The results of the overall state of the secondary medical institutions are shown in The results of the overall state of the tertiary medical institutions are shown in Section 2.3 concerns people employed in the EHC field. The results of the overall state of ENT specialists are shown in The results of the overall state of audiologists are shown in The results of the overall state of speech and audio-verbal therapists are shown in The results of the overall state of hearing aid and earmold technicians are shown in The results of the overall state of teachers of the deaf are shown in The results of the overall state of sign language interpreters are shown in The results of the overall state of general physicians are shown in Health workers, excluding medical personnel  specified in the Medical Act, include emergency medical technicians, caregivers, health education specialists, and practical nurses.The results of the overall state of emergency medical technicians are shown in The results of the overall state of health education specialists are shown in The results of the overall state of caregivers are shown in The results of the overall state of practical nurses are shown in The results of the overall state of hearing aids are shown in Cochlear implants are available in both public health systems and the private sector, similar to hearing aids. This was confirmed in the hospital inquiry service of the Health Insurance Review and Assessment Service, and the guidelines are publicly distributed by Snail of Love, a non-profit organization .The results of the overall state of other assistive devices are shown in The results of the overall state of medicines are shown in The results of the overall state of enactment of the hearing care service are shown in The results of the overall state of health insurance are shown in The results of the overall state of health-related data are shown in The results of the overall state of EHC research are shown in This study aimed to identify the current status of EHC in Korea using EHCSA distributed by the WHO in 2015, compare it with other countries, and establish and improve policies related to medical services and hearing diseases. To this end, we would like to examine various areas, such as domestic health policies, the status of patients with hearing-impairment, and the status of medical personnel, and report to WHO on the state of EHC in Korea.In Iran, a situation analysis was conducted on the domestic ear and hearing care program based on the EHCSA. Through this, inadequate health literacy, weak intra-sectoral and intersectoral cooperation, inadequacy of policy responses, non-integration of the EHC in the primary healthcare system, poor standard processes and resources of EHC, and lack of an EHC surveillance system were identified as major problems . In BangIn contrast, Russia supplemented its nationwide implant and hearing aid programs by introducing a cochlear implant in 1991. Therefore, infants born with hearing impairments could receive hearing aids or cochlear implants and rehabilitation services as needed, and up to 1,100 infants receive cochlear implants each year. In addition, people of all ages can receive hearing tests and hearing aid fitting services at audiological centers, which are paid through the national budget . In the Comparing policies and workforce status in other countries, data, such as Korea's EHC program and workforce status, are at the level of advanced countries. The Ministry of Health and Welfare publishes a health and welfare white paper every year to understand major policies and achievements in the health and welfare sector and to help the government achieve new national goals and tasks. The policies implemented by the Ministry of Health and Welfare, the current status of projects, and plans for implementing new policies are specified. There are child welfare policies, older adult welfare policies, low birth rate measures, disability welfare policies, oral health policies, mental health policies, and herbal medicine policies; however, EHC policies are not implemented or planned, except for innate hearing tests and hearing aid support policies .The Korea Health Industry Promotion Agency's “Hearing Aid Market Analysis” published in 2015 reported that the average growth rate of hearing aids worldwide is 6.9%. Looking at the ranking, Korea showed the fourth-highest growth rate of 8.5% after 18.3% in China, 10.3% in Germany, and 9.1% in France . There aA survey was conducted to investigate the current status of the domestic hearing aid market, and 61.6 and 71.7% of the respondents said they needed an obscure certificate to sell hearing aids in the category of factors that hinder the development of the domestic hearing aid market and need education as a hearing expert, respectively .The above data are not updated continuously, so it is difficult to state that it represents the current situation because it is not the latest data and the survey was conducted with a limited number of people. Therefore, this study is meaningful, and the information on the latest status of the EHC programs was collected. Overall, both the Health workforce and EHC programs are well-prepared, but incidences of hearing diseases, such as hearing loss, are continuously increasing, so various support measures need to be prepared to convert hearing aid-related certificates into national certificates or rehabilitation and support. In addition, domestic health policy improvements and medical service expansion should be achieved through the continuous collection of data on EHC.The original contributions presented in the study are included in the article/The studies involving humans were approved by the Institutional Review Board of Yonsei University Wonju Severance Christian Hospital (CR323326). The studies were conducted in accordance with the local legislation and institutional requirements. Written informed consent for participation was not required from the participants or the participants' legal guardians/next of kin in accordance with the national legislation and institutional requirements.Conceptualization: YS. Data curation: JuhL and JunL. Formal analysis, methodology, and visualization: CY and JuhL. Project administration, writing—reviewing, and editing: CY, YS, SO, and TK. Writing—original draft: JuhL. All authors contributed to the article and approved the submitted version.


This article consists of a scoping review completed to describe the impacts of refurbished hearing aids (HAs) for people with hearing loss, and to identify existing HA refurbishing programs around the world. In this review, JBI methodological guidance for scoping reviews was followed. All types of sources of evidence were considered. Thirty-six sources of evidence were included, 11 articles and 25 web pages. Results suggest that refurbished HAs may improve communication and social participation for individuals with hearing loss and provide monetary savings to them and to governmental agencies. Twenty-five HA refurbishing programs were identified, all based in developed countries and distributing refurbished HAs mostly locally, but also in developing countries. Issues related to refurbished HAs were highlighted, such as potential cross-contamination, quick obsolescence, and repairing problems. Some facilitators for the success of this intervention are to offer accessible and affordable follow-up services, repairs, and batteries, and to ensure awareness and participation of hearing healthcare professionals and citizens with hearing loss. In conclusion, the use of refurbished HAs appears to be a valuable option for low-income people with hearing loss, but it should be included in a more global intervention program to ensure its sustainability. Hearing loss is one of the most common chronic health conditions in the world. According to the World Health Organization (WHO), around 1.5 billion people currently live with it around the world, and it is estimated that this number will be close to 2.5 billion by 2050 ,4. HeariHearing aids (HAs) are the main assistance technology recommended to improve listening and communication for people with hearing loss. Despite their effectiveness to alleviate activity limitations and participation restrictions experienced by those people and to improve quality of life ,9, only Many reasons may explain this discrepancy between HA needs and ownership. Among others are the importance of self-perceived hearing difficulties , the stiThis article presents the results of an exploratory scoping review realized to describe the impacts of HA-refurbishing programs for people with hearing loss, and to identify existing HA refurbishing programs around the world. If the impacts of those programs were mostly positive, and if those programs were better known to the public and hearing healthcare professionals, more people in need would be able to gain access to HAs and to benefit from them, which would improve their social participation and quality of life. Three research questions were explored in this scoping review: (1) What are the advantages and disadvantages of refurbished HAs? (2) What are the determining factors for the success of a HA refurbishing program? (3) What are the existing programs which distribute refurbished HAs to people with hearing loss around the world?A scoping review was conducted , followiTo answer research questions #1 and #2, the following sources of evidence were considered: quantitative, qualitative, and mixed methods research, intervention and descriptive studies, and reviews. To answer research question #3, all sources of evidence were accepted. To be included, sources of evidence had to specifically address the topic of HA refurbishment for participants with hearing loss of all ages, and to present information useful in answer to one of the two research questions. Documents published in English or French in peer-reviewed scientific or professional journals were considered, along with book chapters, conference abstracts, academic theses, web sites, and policy documents.The following databases were consulted: Medline, Embase, CINAHL, PsycINFO, and Web of Science. Each of these data sources were searched using free keywords, combined as follows: [(hearing aid) OR (hearing device) OR (hearing technology) OR (hearing assistance technology) OR (hearing assistive device) OR (hearing assistive aid) OR (assistive listening device) OR (hearing instrument)] AND [(recycl*) OR (refurbish*) OR  OR ]. This search strategy is also presented in Titles of sources of evidence identified with the literature search were reviewed to exclude those that did not meet inclusion criteria. Then, a second validation of inclusion criteria was realized by reviewing the abstracts of the selected articles. This led to a final list of sources of evidence that were included in the complete review process. These sources were read to collect the data pertaining to the research questions. The literature search, the selection of the sources of evidence to be included in the review, and the validation of inclusion criteria were performed independently by two reviewers (VP and LR). At the end of the process, the results of the literature search and the list of studies included by the reviewers were validated by the first author (MH), which led to the final list of included sources of evidence.The data extraction was completed independently by two reviewers (VP and LR). Those reviewers did not use a specific extraction form or checklist for completing this task. They essentially summarized the main results of the included sources of evidence in the form of a narrative literature review (for included articles related to research questions #1 and #2) and of a written description of the identified HA refurbishing programs (in relation to research question #3). Those HA refurbishing programs are also presented in a summary table. When the data extraction was completed by the reviewers, the results were reviewed and validated by the first author (MH).n = 2), qualitative case studies (n = 2), narrative or descriptive reviews (n = 7), or web pages (n = 25). No systematic or scoping review and no experimental or quasi-experimental studies pertaining to HA refurbishing programs were identified. The list of the included sources of evidence related to research questions #1 and #2 is presented in Following the application of the search strategy, 36 sources of evidence were included in the review. Eleven were articles published in scientific or professional journals. Those 11 articles were used to specifically answer research questions #1 and #2. Twenty-five other sources of evidence were web pages presenting HA refurbishing programs. Those 25 web pages were used to answer research question #3 only. The literature search flow chart is presented in Studies were carried out to determine the economic and social benefits that HA-refurbishing programs can have, both for HA recipients and for the government institutions that implant them. Tonning et al.  reviewedThe identified sources of evidence present experiential knowledge about the impacts, advantages, and disadvantages of refurbished HAs for people with hearing loss, mostly gained while implementing and administrating HA refurbishing services in the community. Unsurprisingly, the most important advantage of refurbished HAs is that they are less expensive than new HAs, which allow more people to access this technology. It is estimated that a refurbished HA can be sold at about 2/3 the price of a new one . RefurbiSome disadvantages of refurbished HAs were reported in the literature. Considering the relatively short life cycle of a HA, there is a risk that refurbished HAs become rapidly obsolete due to quick technological advances occurring in the field of hearing amplification . The repA team of researchers studied the facilitating factors and obstacles to implementing a HA recovery-and-refurbishing system in the UK . AccordiAnother determining factor that emerged from Tonning et al.’s  study waWhen a used HA is returned to the distributor, it is not necessarily easy for the professional to know when it is advantageous to refurbish it, or to send it for recycling or disposal. To help professionals make this choice, Rudi et al.  developeFinally, authors mentioned that it is not sufficient to simply distribute refurbished HAs to people in need freely or at a low cost. Accessible and affordable follow-up services, repairs, and batteries are essential for the sustainable use of refurbished HAs ,23,51,52n = 6), in local communities (n = 12), or both (n = 7). All programs targeted low-income patients without other resources available to obtain amplification devices. This implies that patients must qualify to receive refurbished HAs from most programs by filling an application form and sending personal data such as tax slips, an audiogram, and a HA recommendation. Little information is available online about the other characteristics of identified HA refurbishing programs . Some programs were found to have minimum audiometric eligibility criteria [The 25 HA refurbishing programs that were identified during this review were all based in developed countries. They distributed refurbished HAs (mostly BTE HAs) in developing countries  in different health sectors, such as occupational therapy and optometry. A quick look at the literature pertaining to wheelchairs, mobility aids, and eyeglasses refurbishment shows that the offer of those refurbished AT, as for refurbished HAs, allow for meeting the needs of people and may provide monetary savings to governmental agencies and to low-income individuals who have disabilities ,55,56,57As mentioned previously, few scientific data are available about HA refurbishment. In this scoping review, only 11 articles related to research questions were included. Those articles presented results exclusively from quantitative retrospective cross-sectional studies, qualitative case studies, or narrative/descriptive reviews, which are research designs of limited scientific quality. Moreover, information about specific characteristics of many identified HA-refurbishing programs was not accessible on consulted websites. In this context, the results of this review should be interpreted with caution. More research of better quality is needed about HA refurbishing programs. Professionals who might be interested in participating in such initiatives or patients who would like to obtain refurbished HAs are encouraged to contact a local organization for further details.The use of refurbished HAs appears to be a valuable option for low-income people living with hearing loss. It may improve communication and social participation for those individuals and provide monetary savings to them and to governmental agencies which distribute HAs to their population. However, cross-contamination, quick obsolescence, and repairing issues could represent potential problems of refurbished HAs. When implementing a HA-refurbishing program, it is important not only to plan how the HAs will be refurbished and redistributed, but also to determine a clear protocol for HA return and to explore the possibilities of offering accessible and affordable follow-up services, repairs, and batteries. Including the refurbished HAs in a more global intervention program should ensure its sustainability. Awareness and participation of hearing healthcare professionals and of individuals with hearing loss are also critical for the success of such a program. More research is needed on refurbished HAs. Future research should focus on describing and understanding the impacts of the use of refurbished HAs for individuals and the factors associated with the success of this intervention.


The most common complaint among patients with vestibular schwannoma (VS) is hearing loss. This significantly affects the quality of life before, during, and after treatment for patients with VS. Untreated hearing loss in VS patients may even lead to depression and feelings of social isolation. A variety of devices are available for hearing rehabilitation for patients with vestibular schwannoma. These include contralateral routing of hearing signals (CROSs), bone-anchored hearing devices, auditory brainstem implants (ABI), and cochlear implants. In the United States, ABI is approved for patients 12 years of age and older with neurofibromatosis type 2. In the past few years, cochlear implantation has been offered simultaneously or sequentially with tumor resection or irradiation, or even to patients whose VS have been monitored with serial imaging. However, determining the functional integrity of the auditory nerve in patients with vestibular schwannoma is a challenge. This review article consists of (1) the pathophysiology of vestibular schwannoma (VS), (2) hearing loss in VS, (3) treatment of VS and associated hearing loss, (4) options for auditory rehabilitation in patients with VS with their individual benefits and limitations, and (5) challenges in hearing rehabilitation in this cohort of patients to determine auditory nerve functionality. (6) Future directions. Vestibular schwannomas (VS) are benign neoplasms that arise from Schwann cells surrounding the superior or inferior vestibular  nerve ,2. TumorVS can involve a number of different anatomic locations at presentation, including the cerebellopontine angle (CPA), intracanalicular (IC), or intralabyrinthine (IL). While early tumors are frequently isolated to one of these locations, more advanced tumors commonly extend to involve multiple locations. Magnetic resonance imaging (MRI) with and without gadolinium is typically used to detect and characterize these tumors, which dictate treatment and rehabilitative options. The incidence of VS appears to have increased, which may be explained by the increased accessibility to MRI and screening of patients with asymmetrical and/or sudden sensorineural hearing loss ,2. Less Approximately 10% of all intracranial lesions are comprised of VS  and 95% Treatment of sporadic VS consists of a wait-and-scan observation approach or surgical resection or irradiation. The treatment modality depends on the patient’s choice, tumor characteristics . Irradiation of the tumor can be performed with either stereotactic radiosurgery (SRS), gamma knife surgery (GKS), or fractionated stereotactic radiotherapy (FSRT) . The goaHearing rehabilitation is extremely important for all patients with VS to improve their quality of life. However, it is especially important for patients with NF2-associated VS, as they can develop progressive visual disturbances as well as hearing loss. The only available treatment option historically was an auditory brain stem implant (ABI). Today, several options for hearing rehabilitation, besides ABI, can be offered to VS patients that suffer from hearing loss due to the natural history of the tumor or as a result of the treatment modalities. These include conventional hearing aids, contralateral routing of signal (CROS) hearing aids, bone-anchored hearing systems (BAHSs), and cochlear implants (CIs). This review will discuss the benefits and limitations of each of these different auditory rehabilitation options as we seek to improve our ability to affect the quality of life for our VS patients during and after their treatment. Patients with unilateral vestibular schwannoma typically present with asymmetrical sensorineural hearing loss in the affected ear with normal hearing thresholds in the unaffected ear, poor speech discrimination, and tinnitus . ConventCROS hearing aids are used to route sound from the worse-hearing ear to the better-hearing ear and are typical for patients with single-sided deafness. Two different internal devices within the hearing aids themselves are used to execute this contralateral routing process. The first device is inside the hearing aid, which is placed in the worse-hearing ear. It has a microphone that detects sound from that worse-hearing side; however, instead of routing that signal into the worse-hearing ear, similar to what a traditional hearing aid would do, the signal is routed to the opposite (the better-hearing) ear using a transmitter. Thus, sounds and information from the side of the worse-hearing ear are processed through the better-hearing ear.BiCROS is recommended for patients with mild-to-moderate hearing loss in the contralateral ear, as compared to a normal-hearing contralateral ear for CROS. Historically, only a small percentage of patients with single-sided deafness (SSD) reported improvement in their quality of life with the use of CROS or BiCROS . This maAdvances in CROS hearing aid system technology have addressed previous limitations, such as short battery life, poor sound quality, discomfort, and aesthetics due to their large size. The addition of wireless streaming allows the sound signal to be transmitted to the better-hearing ear without delays or audible interference . AdvanceBone-anchored hearing systems are surgical solutions used to mitigate unilateral hearing loss in patients with VS. It consists of a titanium screw or plate fixed to the bone behind the ear, and it connects either percutaneously or transcutaneously to an external bone oscillator. The microphone, which receives the sound signal, is integrated into the bone oscillator. The sound processor transforms the signal into an oscillatory signal, which is transmitted through the plate/screw, which in turn causes the bone to vibrate at a certain frequency and send a signal into the cochlea on the better hearing side. Unlike the CROS hearing aid, which uses air conduction, the BAHS uses bone conduction for sound transmission. BAHS works best for patients with VS who have good contralateral hearing. Additionally, similar to CROS hearing aids, BAHS is limited by its inability to provide binaural hearing, which is important for sound localization and improving speech understanding in noise . HoweverThe wide variety of BAHS devices may be categorized into percutaneous or transcutaneous, and within the transcutaneous category, there are surgical and nonsurgical options. The variety of BAHS devices that are available, make for many different rehabilitative options for both pediatric and adult VS patients, as well as those who are unable to undergo surgery.ABI is a surgically implanted device that bypasses the cochlear nerve to electrically stimulate the neurons in the brain stem dorsal cochlear nucleus. For a long time, ABI was the only treatment for hearing rehabilitation for patients with hearing loss caused by VS. The ABI electrodes are embedded in a silastic paddle and placed in the fourth ventricle. The device has an external battery, a microphone, a speech processor, a transmitter coil, and a magnet that is worn behind the ear. ABI has been approved by the US FDA for use in patients age 12 and older with NF2 for hearing rehabilitation. Patients with ABI typically have sound awareness, but results with ABI have been modest, and open-set speech  after ABI is an exception ,24. LessABI is a great treatment option when the cochlear nerve has been rendered absent or nonfunctional; however, determining the status of the cochlear nerve remains a challenge. We must establish a standardized method of testing the cochlear nerve for functional integrity during and/or after observation or treatment for VS. This will allow a better treatment algorithm to be established and help us determine exactly who might benefit from CI over ABI. Since ABI surgery is more invasive than CI surgery, it should only be considered in appropriate patients who would not benefit from CI. Currently, though, our ability to make that determination on a consistent basis remains somewhat limited.Cueva et al. in 1992 reported data from six patients with grossly intact cochlear nerves and anacusis after resection of VS who were able to perceive sound following the electrical promontory stimulation. They postulated that these patients could potentially benefit from cochlear implantation . SubsequSince then, several studies have demonstrated CI to be an effective means for auditory rehabilitation in patients with sporadic unilateral VS as well as NF2 patients after microsurgical resection or radiation therapy ,30,31,32The CI electrically stimulates the cochlear nerve in the inner ear to enable identification, interpretation, and associating meaning with the sound (auditory perception). This is unlike the ABI, which stimulates the neurons of the dorsal cochlear nucleus in the brain stem. CI is a device consisting of a surgically implanted electrode array with a receiver-stimulator coupled with an external sound processor. The microphone on the external processor receives sound and converts it to an electrical signal, which is carried to the spiral ganglion cells of the cochlear nerve via a multielectrode array. Cochlear implant electrode arrays utilize the tonotopic organization of the cochlea to maximize sound intelligibility by covering almost the entire spectrum of perceivable auditory frequencies. For a cochlear implant to be effective, cochlear nerve integrity is essential and may play a role in hearing outcomes after CI in VS patients. This means that any therapeutic modality offered to treat VS must also be able to preserve cochlear nerve integrity. Even if the cochlear nerve is preserved during surgical resection, it has been shown that a majority of those patients can go on to lose their hearing . SeveralDetermining the functional integrity of the cochlear nerve has always presented a challenge. The electrical promontory stimulation (EPS) test is a test that has been used traditionally to determine the functionality of the cochlear nerve. It is performed by placing a transtympanic needle electrode on the surface of the cochlea, and the cochlea nerve is electrically stimulated through the monitoring of subjective and electrically evoked auditory brainstem responses. A loss of neural integrity at the spiral ganglion or cochlear nerve level is indicated by an absence of response to stimulation. On the other hand, the presence of a response is indicative of vascular compromise of the cochlea with the sparing of the spiral ganglion and the cochlear nerve. This test has its drawbacks, as some patients with good EPS do not benefit from a CI, while some with poor EPS have achieved open-set speech with a CI ,27,29.In a large systematic review, 65% of patients with NF2 who underwent surgical resection with ipsilateral cochlear implantation were found to have developed open-set speech with the CI . InteresVS are benign, slow-growing tumors. Their growth pattern causes a mass effect on surrounding neural structures. Patients commonly have hearing loss. Sporadic VS is unilateral versus bilateral in patients with neurofibromatosis type 2. Hearing loss in these patients can occur due to compression of the auditory nerve by the tumor with subsequent cochlear dysfunction , moleculHearing loss and tinnitus in sporadic and NF2 patients affect their quality of life irrespective of whether the treatment approach is observational, surgical resection, or radiation. The wait-and-scan approach is recommended for VS less than 1.5 cm in diameter, with a slow or no growth pattern, or in elderly patients who do not want to undergo surgery. Studies have reported irreversible hearing loss in these patients, even during observation . Ariano CROS, BiCROS, BAHS, CI, and ABI are all feasible options in patients with sporadic VS and NF2 when appropriately selected to address the severity, type of patient’s hearing loss, and integrity of the cochlear nerve after tumor resection . HearingIn a survey of patients with unilateral VS, the majority (88%) of the patients reported being able to hear “poorly” or “not at all” in the ipsilateral ear. However, the authors found that less than one-third of the patients pursued hearing rehabilitation. They were neither bothered by their hearing loss nor aware of the options for hearing rehabilitation . ApproxiFor a long time, ABI was the only treatment option for hearing rehabilitation for VS patients with hearing loss. They are implanted simultaneously or sequentially after tumor resection. They can help VS patients lip read and identify environmental sounds, but less than 5% of NF2 patients have open-set speech ,24. In tThe cochlear nerve must be anatomically and functionally intact for the cochlear implant to provide benefit to the patient. One of the main limitations of CI in the hearing rehabilitation of patients with VS continues to be the assurance of the functionality of the cochlear nerve. Several studies are ongoing to develop a testing method for monitoring auditory nerve function in these patients ,45,47. MA systematic review of various cochlear monitoring techniques, such as auditory brainstem responses (ABR), direct eight cranial nerve monitoring (DENM), distortion product otoacoustic emissions (DPOAE), and postauricular muscle responses (PAMRs), reported that the outcomes of cochlear nerve monitoring were satisfactory with all techniques. However, none of the techniques could be rated superior to the others due to the heterogeneity of reporting the outcomes of the techniques in the literature . To deteThe devices/options for auditory rehabilitation in VS patients vary greatly, however, they can be grouped into three categories: (1) air conduction devices, including CROS and BiCROS hearing aids, (2) bone conduction devices, for which there are surgical and nonsurgical modalities, and (3) electrical conduction devices, which include ABI and CI. It is important to have different treatment options to fit the needs of each individual patient. By increasing awareness of the options for auditory rehab in VS patients, we may improve our ability to assist this patient population through the exciting technologies that have been developed and employed in recent years.Of all available options for auditory rehabilitation in VS patients, CI currently has the most potential for improvement in open-set speech, improvement to speech understanding in noise, and improvement to sound localization/binaural hearing. Currently, though, our ability to offer CI to our VS patients is mainly limited by concerns about the current or future status of their cochlear nerve, whether they undergo observation or treatment. Technologies have been developed to confirm cochlear nerve functionality intraoperatively, which has changed our approach to auditory rehabilitation in VS patients. As a result of this technology, patients have been able to receive simultaneous tumor resection and cochlear implantation, which has demonstrated promising and interesting results to date.Multiple other neoplastic conditions elsewhere in the body are treated with simultaneous resection and rehabilitation. This type of treatment planning is unique in that it not only leads to tumor control, but simultaneously improves the quality of life for our patients as they go through these debilitating conditions, such as VS. Further research is needed to better standardize the testing for the functional integrity of the cochlear nerve after resection or radiation in hopes of improving hearing rehabilitation options for patients with both unilateral and bilateral VS in the future.Something that will be imperative in helping maximize the number of patients that may benefit from simultaneous resection and CI implantation in the future is diagnosing these tumors in a timely manner and moving forward with treatment while hearing remains serviceable. As such, MRI imaging for at-risk patients remains critical to the care of this patient population.As implantable/wearable device technology continues to improve, it continues to interface not only with the human body more effectively, but also with other forms of technology in our environment as well, and this will one day make the rehabilitative process for our VS patients more seamless than ever as they go through surveillance and/or treatment and recovery.