Cochlear Implantation in the Poorer-Hearing Ear Is a Reasonable Choice.

Choosing the optimal side for cochlear implantation (CI) remains a major challenge because of the lack of evidence. We investigated the choice of the surgery side for CI (i.e., the better- or poorer-hearing ear) in patients with asymmetric hearing. Audiological records of 74 adults with a unilateral hearing aid who had undergone surgery at Okayama University Hospital were reviewed. The definition of 'better-hearing ear' was the aided ear, and the unaided ear was considered the poorer-hearing ear. We performed a multiple regression analysis to identify potential predictors of speech recognition performance after unilateral CI in the patients. Fifty-two patients underwent CI in the poorer-hearing ear. The post-Ci bimodal hearing rate was far higher in the poorer-ear group (77.8% vs. 22.2%). A multivariate analysis revealed that prelingual hearing loss and the patient's age at CI significantly affected the speech recognition outcome (beta coefficients: 24.6 and -0.33, 95% confidence intervals [11.75-37.45] and [-0.58 to -0.09], respectively), but the CI surgery side did not (-6.76, [-14.92-1.39]). Unilateral CI in the poorer-hearing ear may therefore be a reasonable choice for adult patients with postlingual severe hearing loss, providing a greater opportunity for postoperative bimodal hearing.

Detailed clinical features and genotype-phenotype correlation in an OTOF-related hearing loss cohort in Japan.

Mutations in the OTOF gene are a common cause of hereditary hearing loss and the main cause of auditory neuropathy spectrum disorder (ANSD). Although it is reported that most of the patients with OTOF mutations have stable, congenital or prelingual onset severe-to-profound hearing loss, some patients show atypical clinical phenotypes, and the genotype-phenotype correlation in patients with OTOF mutations is not yet fully understood. In this study, we aimed to reveal detailed clinical characteristics of OTOF-related hearing loss patients and the genotype-phenotype correlation. Detailed clinical information was available for 64 patients in our database who were diagnosed with OTOF-related hearing loss. As reported previously, most of the patients (90.6%) showed a "typical" phenotype; prelingual and severe-to-profound hearing loss. Forty-seven patients (73.4%) underwent cochlear implantation surgery and showed successful outcomes; approximately 85-90% of the patients showed a hearing level of 20-39 dB with cochlear implant and a Categories of Auditory Performance (CAP) scale level 6 or better. Although truncating mutations and p.Arg1939Gln were clearly related to severe phenotype, almost half of the patients with one or more non-truncating mutations showed mild-to-moderate hearing loss. Notably, patients with p.His513Arg, p.Ile1573Thr and p.Glu1910Lys showed "true" auditory neuropathy-like clinical characteristics. In this study, we have clarified genotype-phenotype correlation and efficacy of cochlear implantation for OTOF-related hearing loss patients in the biggest cohort studied to date. We believe that the clinical characteristics and genotype-phenotype correlation found in this study will support preoperative counseling and appropriate intervention for OTOF-related hearing loss patients.

Effects of Protective Measures against COVID-19 on Auditory Communication for People with Hearing Loss.

WHO has recommended various measures to combat the COVID-19 pandemic, including mask-wearing and physical distancing. However, these changes impair communication for individuals with hearing loss. We investigated the changes in auditory communication associated with COVID-19 measures in 269 patients (male: 45.7%, female: 54.3%, median age: 54 y.o.). Most patients with hearing loss had difficulty engaging in auditory communication with people wearing masks, especially in noisy surroundings or with physical distanc-ing. These difficulties were noticeable in patients with severe hearing loss. Developing communication support strategies for people with hearing loss is an urgent need while COVID-19 measures are in place.

Genetic Counseling of a Hearing-impaired Patient with Multiple Genetic Mutations.

Since April 2012, genetic testing for congenital hearing loss is covered by the public health insurance in Japan. Recent (since August 2015) developments in next-generation sequencing technology have enabled the detection of 154 mutations in 19 genes. Genetic testing provides valuable information on hearing phenotype, prognosis, and prediction of associated symptoms. We report a hearing-impaired patient in whom multiple genetic mutations were detected. This patient carries two missense mutations in GJB2 (p.G45E, p.Y136X), as well as a mitochondrial mutation (7445A>G). Since the number of genes detectable by genetic testing has increased, the diagnosis of hearing loss can be made with greater accuracy. However, it is often difficult to clinically understand and interpret the genotype information, especially when multiple gene variants are detected in one patient or family. Genetic counseling plays an important part in the intervention for or follow-up of such patients. Genotypic and phenotypic information of other family members is necessary, so that both the patient and the family can understand and accept the results of genetic testing.

[Assessment of hearing aid outcome using CADL].

The presence of hearing impairment deteriorates patients' quality of life by affecting their daily-life communication. Several self-report assessments are available to evaluate the subjective outcome of hearing aids, however, the procedures to evaluate the impairment of communication induced by hearing impairment has not been well established. A PC-recorded audio file prepared to evaluate the communication ability of hearing aid users, by extracting fifteen spoken language items from the Communication ADL Test: sp-CADL. A before and after study was performed among the hearing aid users who were attending Okayama University Hospital to evaluate the improvement in each of the 15 sp-CADL scores. Twenty-one adults were included in this study whose age ranged from 22 to 83 years old (mean: 56.7 years old). The total and individual scores of the sp-CADL improved significantly after the use of the hearing aids (p < 0.05). The total sp-CADL score of the patients with hearing aids showed a good correlation with the best scores of the speech discrimination test measured before wearing hearing aids.

[The age at which the grade of Special Child Dependent's Allowance Act can be judged in the case of deaf children].

The spread of neonatal hearing screening has made the identification of hearing loss in early childhood possible, and most of the children with hearing loss are diagnosed and provided with early intervention within several months after their birth. However, they have to wait to receive the Special Child Dependent's Allowance until their hearing levels are evaluated with audiometers. Under the Special Child Dependent's Allowance Act now in force, a delay of several years occurs for those children before they can receive the allowance after diagnosis. We retrospectively reviewed hearing test results of children who had not reacted at 90dBnHL bilaterally in ABR within 12 months after birth, and examined when those results were certain enough to determine their allowance eligibility. We found that the eligibility in children with hearing loss alone could be determined at 1 year of age; as for children who had other disorders, since it was mostly difficult to test them with an audiometer, the diagnosis of hearing loss must always be made carefully but it was also possible to determine the eligibility for the allowance at 1 year of age.

15-year follow-up for steroid-responsive, fluctuating hearing loss in the ear with endolymphatic hydrops confirmed by magnetic resonance imaging.

Autoimmune mechanisms may play crucial roles in the etiology of endolymphatic hydrops (ELH), which was previously regarded as a postmortem finding in the temporal bone. Recently, ELH has been visualized using 3-T MR imaging in living patients. A 47-year-old woman with deafness in the left ear since adolescence developed right-sided steroid-responsive sensorineural hearing loss in the low frequencies. During over 15 years of follow-up at our otolaryngology clinic, acute deteriorations of hearing in the only hearing ear repeatedly recovered with administration of intravenous and oral steroids. Hearing in the only hearing ear at 62 years old was preserved and comparable to that at 47 years old. At 61 years old, cochlear ELH was documented bilaterally on MR imaging, appearing more severe in the deafened ear than in the hearing ear. This case provides new evidence of the potential steroid-responsiveness of hearing loss due to contralateral-type delayed ELH distinctly visualized on MR imaging.

Endolymphatic Hydrops on Magnetic Resonance Imaging May Be an Independent Finding on Aging in Neurotologic Patients.

OBJECTIVE: To clarify whether age impacts the development of endolymphatic hydrops (ELH) in neurotologic patients. Documentation of ELH in living patients on magnetic resonance imaging (MRI) allows analysis of patient age and formation of ELH, which is impossible by means of postmortem temporal bone pathology. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Fifty patients (100 ears) with top 3 diagnoses of definite Menière's disease, delayed ELH, or probable Menière's disease. INTERVENTIONS: Endolymph MRI after intravenous gadolinium injection and pure-tone audiometry. MAIN OUTCOME MEASURES: Cochlear and vestibular ELH confirmed by MRI. RESULTS: The prevalences of ears showing both cochlear and vestibular ELH were similar among age groups <30 years (30%), 30-59 years (25.9%), and ≥60 years (34.4%; p > 0.05; χ2 test). Using logistic regression modeling, mean hearing level at the six frequencies was positively associated with a higher risk of cochlear ELH (odds ratio, 1.3; 95% confidence interval, 1.1-1.5 per 10-dB increment). In the same regression model, age did not impact the outcome of cochlear ELH (odds ratio, 1.0; 95%confidence interval, 0.7-1.4 per 10-year increment). Age did not differ among ears with no ELH (mean ± standard deviation age, 48.6 ± 14.4 yr), ears with only cochlear ELH (59.3 ± 10.7 yr), ears with only vestibular ELH (50.4 ± 16.9 yr), or ears with both cochlear and vestibular ELH (51.5 ± 18.4 yr; p > 0.05, analysis of variance). CONCLUSION: Chronological age was not associated with the formation of ELH. Aging per se may not be associated with the development of ELH in neurotologic patients.

Relationship between spontaneous nystagmus and video Head Impulse Test findings among patients with chronic neurotologic conditions.

The vestibulo-ocular reflex (VOR) in neurotologic patients can be evaluated most quickly by spontaneous nystagmus examinations, and the video Head Impulse Test (vHIT) quantitatively evaluates the VOR of the semicircular canals. We aimed to clarify the concordance and discrepancies between spontaneous nystagmus and vHIT findings, to provide guidance on screening vestibular functions by initial spontaneous nystagmus examination then vHIT. We evaluated 169 outpatients by spontaneous nystagmus examination in the dark using a charge-coupled device camera, then by horizontal vHIT the same day. Vestibular loss on vHIT was defined if both reduced VOR gain (<0.8) and corrective saccade were observed. Adjusted logistic regression modelling revealed that differences in right and left VOR gain positively impacted the presence of nystagmus, which suggests lateralised vestibular dysfunction (P<0.05; odds ratio 1.39 [95% confidence interval, 1.1-1.8] per 0.1 increment). When vHIT is regarded as the standard clinical test, the positive predictive value of nystagmus for vestibular loss on vHIT was 44.4%, and the negative predictive value was 93.5%. The adjusted odds ratio of adults ≥65 years old compared to younger patients associated with a discrepancy of nystagmus and vHIT was significant (2.4 [1.1-5.3]). In conclusion, if spontaneous nystagmus is initially observed in patients, further assessment by vHIT could confirm vestibular dysfunction in 40-50% of cases. If no nystagmus is observed, vHIT might also result in a negative finding in >90% of cases. Older adults appear more likely to show discrepancies between nystagmus and vHIT.

Static posturographic balance in neurotologic patients may be associated with middle-high-frequency hearing levels during ageing process.

BACKGROUND: Understanding how sensorineural hearing loss (SNHL) impacts postural balance in patients is important, as postural balance predicts the risk of falls. AIMS/OBJECTIVES: We aimed to clarify the relationship between characteristics in the configuration of audiograms and static postural balance as measured by posturography. MATERIALS AND METHODS: We evaluated 385 outpatients (mean [± standard deviation] age, 58.4 ± 18.4 years) with SNHL by audiometry and posturography. Data were analysed by multiple regression models with the outcome of postural sway area with eyes closed (PSA) and predictive variables of audiometric data, adjusted for sex, age and the presence of nystagmus. RESULTS: The increased hearing threshold in the better hearing ear was associated with poorer or higher PSA (beta coefficient [ß] = 0.39, 95% confidence interval [CI] = 0.03-0.75, per 10-dB increment). No difference in PSA was detected between patients with asymmetric or symmetric SNHL. None of the frequent diagnoses (presbyacusis, Meniere's disease, and idiopathic sudden SNHL) were associated with poorer PSA. Hearing thresholds at middle (ß = 0.39, 95%CI = 0.10-0.67) and high frequencies (ß = 0.31, 95%CI = 0.07-0.55) were associated with poorer PSA, whereas those at low frequencies was not. CONCLUSIONS AND SIGNIFICANCE: Postural balance in neurotologic patients may be associated with middle-high-frequency hearing levels during ageing.

[Progressive or delayed early-onset pediatric sensorineural hearing loss].

The introduction of newborn-hearing screening has enabled early childhood hearing loss to be diagnosed and increased the number of children undergoing early care. Bilateral hearing loss is found in 0.08% of newborns and children whose hearing loss progresses or onset is delayed account for 4 to 30% of all pediatric hearing impairment. Children with perinatal risk factors tend to have deteriorated hearing or delayed-onset hearing loss in early childhood, necessitating audiometric follow-up. We also are aware of some children without risk factors who develop hearing impairment during infancy or early childhood. Hearing deterioration may be difficult to diagnose objectively, especially in young children, the presence of risk factors must be determines as soon as possible, especially given the lack of hearing management and close examination of children without apparent risk factors. We retrospectively studied children born from April 1998 to March 2007 and undergoing cochlear implantation as of April 2008. Among cases, we focused on 10 whose hearing impairment advanced during infancy -4 with risk factors known before hearing deterioration progressed, and 6 cases thought not to have any risk factors. We detected enlarged vestibular acquaduct in 3 of these 6 cases, and 3 more of whom had no risk factors -2 passing newborn-hearing screening and 1 in whom such screening detected hemilateral hearing loss. Our results underscore the need for early temporal computed tomography for detecting enlarged vestibular aquaduct. Even children with mild or hemilateral hearing loss should undergo audiometric and developmental testing at least every 6 months up to going to elementary school. Children suspected of impaired hearing should undergo thorough hearing tests regardless of newborn hearing-screening results to catch any problems early. Appropriate regular hearing and language development check-up tests must also be developed.

[Subsidizing hearing aid purchase in mild to moderate pediatric hearing--pediatric status following prefectural assembly subvention].

The dissemination of newborn hearing screening (NHS) has enabled those with mild to moderate hearing loss to be diagnosed in early infancy. The "handicapped independence support law", however, prevents those not determined to be physically handicapped; i.e., those with mild to moderate hearing loss-, from government assistance in purchasing hearing aids. This results either in (i) parents purchasing hearing aids at their own expense or (ii) nonpurchase of hearing aids. To redress this situation, subvention in purchasing hearing aids of mild to moderate hearing loss children has been begun by some local governments. We petitioned for such aid at the Okayama Prefecture Assembly. A society for supporting pediatric hearing difficulty in Okayama Prefecture also submitted a similar petition in September 2009, and subvention began in April 2010 for all such children in Okayama Prefecture. We report procedures and details leading to this subvention.

Subjective Evaluation of Balance by the Dizziness Handicap Inventory Does Not Predict Fall Risk in Older Adults Visiting Otolaryngology Clinics.

OBJECTIVES: Subjective symptoms of dizziness in older adults are affected not only by objective data such as postural balance, but also by complex psychological factors. Published data analyzing how simultaneous evaluations of both objective and subjective assessments of balance can predict fall risk remain lacking. This study examined how fall risk can be predicted based on both objective data for balance and hearing and subjective symptoms of dizziness among older adults visiting otolaryngology clinics. METHODS: Medical charts of 76 patients ≥65 years old with dizziness/vertigo who visited the otolaryngology clinic were reviewed. Objective data were evaluated by postural balance (posturographic data with eyes open and closed, and one-leg standing test), spontaneous nystagmus, and mean hearing levels. Subjective handicap associated with dizziness/vertigo was assessed using the Dizziness Handicap Inventory (DHI). Subjective mental status of anxiety and depression were assessed using the Hospital Anxiety and Depression Scale (HADS). Information on history (cardiovascular diseases) and fall accidents within the preceding year was collected using an in-house interview sheet. RESULTS: Objective data on postural balance did not correlate with subjective symptoms on DHI or HADS (P > .05, Pearson's correlation coefficient). Adjusted logistic regression modeling with the outcome of incident falls revealed that poor postural balance significantly predicted fall risk (P < .05; 4.9 [1.4-16.8] per 10-cm2 increment). Nystagmus tended to be associated with fall risk. In contrast, DHI score did not predict fall risk (P = .43; 1.0 [0.9-1.03]). Receiver operating characteristic analysis proposed a cut-off for postural sway with eyes closed >6.1 cm2 as optimal to predict falls in patients with nystagmus (AUC, 0.74; 95% confidence interval, 0.48-0.997). CONCLUSION: Poor postural balance is associated with increased fall risk after adjusting for subjective symptoms in older adults at otolaryngology clinics. Conversely, the self-perceived dizziness handicap of DHI score is an insufficient tool to evaluate their fall risk.

Immediate changes in transcription factors and synaptic transmission in the cochlea following acoustic trauma: A gene transcriptome study.

Pathologic mechanisms in cochleae immediately following the onset of noise-induced hearing loss (NIHL) remain unclear. In this study, mice were exposed to 120 dB of octave band noise for 2 h to induce NIHL. Three hours after noise exposure, expression levels of the whole mouse genome in cochleae were analyzed by RNA-seq and DNA microarray. Differentially expressed genes (DEGs) exhibiting >2-fold upregulation or downregulation in noise-exposed cochleae compared to controls without noise exposure were identified. RNA-seq and microarray analyses identified 273 DEGs regulated at 3 h post-noise (51 upregulated and 222 downregulated). Bioinformatic analysis revealed that these DEGs were associated with the functional gene pathway "neuroactive ligand-receptor interaction" and included 28 genes encoding receptors for neurotransmitters such as gamma-aminobutyric acid and glutamate. Other DEGs included 25 genes encoding transcription factors. Downregulation of 4 neurotransmitter receptors (Gabra3, Gabra5, Gabrb1, Grm1) and upregulations of 5 transcription factors (Atf3, Dbp, Helt, Maff, Nr1d1) were validated by RT-PCR. The differentially regulated transcription factor Atf3 immunolocalized to supporting cells and hair cells in the organ of Corti at 12-h post-noise. The present data serve as a basis for further studies aimed at developing medical treatments for acute sensorineural hearing loss.

Lack of collagen α6(IV) chain in mice does not cause severe-to-profound hearing loss or cochlear malformation, a distinct phenotype from nonsyndromic hearing loss with COL4A6 missense mutation.

Congenital hearing loss affects 1 in every 1000 births, with genetic mutations contributing to more than 50% of all cases. X-linked nonsyndromic hereditary hearing loss is associated with six loci (DFNX1-6) and five genes. Recently, the missense mutation (c.1771G>A, p.Gly591Ser) in COL4A6, encoding the basement membrane (BM) collagen α6(IV) chain, was shown to be associated with X-linked congenital nonsyndromic hearing loss with cochlear malformation. However, the mechanism by which the COL4A6 mutation impacts hereditary hearing loss has not yet been elucidated. Herein, we investigated Col4a6 knockout (KO) effects on hearing function and cochlear formation in mice. Immunohistochemistry showed that the collagen α6(IV) chain was distributed throughout the mouse cochlea within subepithelial BMs underlying the interdental cells, inner sulcus cells, basilar membrane, outer sulcus cells, root cells, Reissner's membrane, and perivascular BMs in the spiral limbus, spiral ligament, and stria vascularis. However, the click-evoked auditory brainstem response analysis did not show significant changes in the hearing threshold of Col4a6 KO mice compared with wild-type (WT) mice with the same genetic background. In addition, the cochlear structures of Col4a6 KO mice did not exhibit morphological alterations, according to the results of high-resolution micro-computed tomography and histology. Hence, loss of Col4a6 gene expression in mice showed normal click ABR thresholds and normal cochlear formation, which differs from humans with the COL4A6 missense mutation c.1771G>A, p.Gly591Ser. Therefore, the deleterious effects in the auditory system caused by the missense mutation in COL4A6 are likely due to the dominant-negative effects of the α6(IV) chain and/or α5α6α5(IV) heterotrimer with an aberrant structure that would not occur in cases with loss of gene expression.

Upregulation of a nuclear factor-kappa B-interacting immune gene network in mice cochleae with age-related hearing loss.

Epidemiological data suggest that inflammation and innate immunity play significant roles in the pathogenesis of age-related hearing loss (ARHL) in humans. In this mouse study, real-time RT-PCR array targeting 84 immune-related genes revealed that the expressions of 40 genes (47.6%) were differentially regulated with greater than a twofold change in 12-month-old cochleae with ARHL relative to young control mice, 33 (39.3%) of which were upregulated. These differentially regulated genes (DEGs) were involved in functional pathways for cytokine-cytokine receptor interaction, chemokine signaling, TNF signaling, and Toll-like receptor signaling. An NF-κB subunit, Nfkb1, was upregulated in aged cochleae, and bioinformatic analyses predicted that NF-κB would interact with the genomic regulatory regions of eight upregulated DEGs, including Tnf and Ptgs2. In aging cochleae, major proinflammatory molecules, IL1B and IL18rap, were upregulated by 6 months of age and thereafter. Remarkable upregulations of seven immune-related genes (Casp1, IL18r1, IL1B, Card9, Clec4e, Ifit1, and Tlr9) occurred at an advanced stage (between 9 and 12 months of age) of ARHL. Immunohistochemistry analysis of cochlear sections from the 12-month-old mice indicated that IL-18r1 and IL-1B were localized to the spiral ligament, spiral limbus, and organ of Corti. The two NF-κB-interacting inflammatory molecules, TNFα and PTGS2, immunolocalized ubiquitously in cochlear structures, including the lateral wall (the stria vascularis and spiral ligament), in the histological sections of aged cochleae. IBA1-positive macrophages were observed in the stria vascularis and spiral ligament in aged mice. Therefore, inflammatory and immune reactions are modulated in aged cochlear tissues with ARHL.

A Multi-Institutional Study of Older Hearing Aids Beginners-A Prospective Single-Arm Observation on Executive Function and Social Interaction.

OBJECTIVES: To obtain new insights into research questions on how executive function and social interaction would be observed to change after the introduction of hearing aids (HAs) in older people with hearing impairment. DESIGN: Multi-institutional prospective single-arm observational study. SETTING AND PARTICIPANTS: Outpatients with complaints of hearing difficulty who visited HA clinics between October 18, 2017, and June 30, 2019, in 7 different university hospitals in Japan. METHODS: The inclusion criteria of the study named Hearing-Aid Introduction for Hearing-Impaired Seniors to Realize a Productive Aging Society-A Study Focusing on Executive Function and Social Activities Study (HA-ProA study) were age ≥60 years and no history of HA use. A series of multi-institution common evaluations including audiometric measurements, the digit symbol substitution test to assess executive functions, convoy model as an index of social relations, and hearing handicap inventory for the elderly (HHIE) were performed before (pre-HA) and after 6 months of the HA introduction (post-HA). RESULTS: Out of 127 enrollments, 94 participants completed a 6-month follow-up, with a mean age of 76.9 years. The digit symbol substitution test score improved significantly from 44.7 at baseline to 46.1 at 6 months (P = .0106). In the convoy model, the social network size indicated by the number of persons in each and whole circles were not significantly different between pre- and post-HA; however, the total count for kin was significantly increased (P = .0344). In the analyses of HHIE, the items regarding the family and relatives showed significant improvement. CONCLUSIONS AND IMPLICATIONS: HA use could benefit older individuals beginning to use HAs in executive function and social interaction, though the results should be interpreted cautiously given methodological limitations such as a single-arm short 6 months observation. Reduction in daily hearing impairment would have a favorable effect on relationships with the family.

Comparing the cochlear spiral modiolar artery in type-1 and type-2 diabetes mellitus:a human temporal bone study.

This study examined whether pathological findings were present in cochlear vessels for patients with diabetes mellitus. Twenty-six temporal bones from 13 patients with type 1 diabetes mellitus and 40 temporal bones from 20 patients with type 2 diabetes mellitus were examined. Type 2 diabetic temporal bones were divided into 2 groups according to diabetic management (22 temporal bones with insulin therapy, and 18 with oral hypoglycemic drugs). Age-matched normal control temporal bones were also selected. The vessel wall thickness in the cochlear spiral modiolar artery was measured under a light microscope, and the vessel wall ratio (vessel wall thickness/outer diameter of the vessel x 100) was calculated. The vessel wall thickness and vessel wall ratio in type 1 diabetes mellitus were significantly greater than in normal controls. Type 2 diabetic patients with insulin therapy showed significantly greater vessel wall thickness and vessel wall ratios than controls. In type 2 diabetes mellitus, the vessel wall thickness and vessel wall ratio were greater in patients treated with insulin therapy than in those treated with oral hypoglycemic agents. Type 2 diabetic patients with insulin therapy showed an increased vessel wall thickness and vessel wall ratio compared to patients with type 1 diabetes mellitus. In conclusion, the cochlea in patients with diabetes mellitus shows circulatory disturbance compared to age-matched normal controls.

Prevalence and risk factors for delayed-onset hearing loss in early childhood: A population-based observational study in Okayama Prefecture, Japan.

OBJECTIVES: The aim of this study was to retrospectively document prevalence rates of delayed-onset hearing loss (DOHL) under 7 years old after passing the newborn hearing screening (NHS) program using its database in Okayama Prefecture, as well as records from Okayama Kanariya Gakuen (OKG, Auditory Center for Hearing Impaired Children, Okayama Prefecture, Japan). We explored the percentage of children with DOHL among all children who underwent the NHS and surveyed risk factors abstracted from their clinical records. METHODS: We collected data of 1171 children, who first visited OKG from April 2006 to March 2018. DOHL children were defined as bilaterally hearing-impaired children who were diagnosed under 7 years old after passing the NHS at birth. Based on the medical records, we investigated age at diagnosis, hearing levels, and risk factors. As population-based data of 168,104 children, the percentage of DOHL subjects was retrospectively calculated among the total number of children who underwent the NHS in Okayama Prefecture from April 2005 to March 2017. RESULTS: During the period, we identified 96 children with bilateral DOHL, of which 34 children had failed the NHS unilaterally and 62 had passed the NHS bilaterally. Among all children who underwent the NHS in Okayama Prefecture, the prevalence rate of DOHL in unilaterally referred infants was 5.2%, and 0.037% in bilaterally passed children. The prevalence of bilateral DOHL was 0.057% overall. Unilaterally referred children with DOHL were diagnosed at an average of 13.9 months, while bilaterally passed children with DOHL were diagnosed at an average of 42.3 months. Approximately 59.4% of children with DOHL had risk factors, among which family history of hearing loss was the most frequent. CONCLUSION: We propose the first English report of DOHL prevalence in the prefecture population in Japann, which is among the largest community-based population ever reported. The NHS is not a perfect strategy to detect all early-childhood hearing loss; therefore, careful assessment of hearing throughout childhood is recommended, especially in children with risk factors of hearing loss. Further interventional strategies must be established, such as regular hearing screening in high-risk children and assessments of hearing and speech/language development in public communities and nursery schools.