The prevalence of hearing loss and use of hearing aids among adults in Germany: a systematic review

miR-130b-3p involved in the pathogenesis of age-related hearing loss via targeting PPARγ and autophagy

The study focuses on the underlying regulatory mechanism of age-related hearing loss (ARHL), which results from autophagy dysregulation mediated by miR-130b-3p targeting PPARγ. We constructed miR-130b-3p knockout (antagomir) and PPARγ over-expression (OE-PPARγ) mice model by injecting mmu-miR-130b-3p antagomir and HBAAV2/Anc80-m-Pparg-T2A-mCHerry into the right ear' round window of each mouse, respectively. In vitro, we introduced oxidative stress within HEI-OC1 cells by H2O2 and exogenously changed the miR-130b-3p and PPARγ levels. MiRNA level was detected by RT-qPCR, proteins by western blotting and immunohistochemistry. Morphology of autophagosomes was observed by electron microscopy. In vivo, the cochlea of aged mice showed higher miR-130b-3p expression and lower PPARγ expression, while exogenous inhibition of miR-130b-3p up-regulated PPARγ expression. Autophagy-related biomarkers expression (ATG5, Beclin-1 and LC3B II/I) decreased in aged mice, which reversely increased after the inhibition of miR-130b-3p. The elevation of PPARγ demonstrated similar effects. Contrarily, exogenous overexpression of miR-130b-3p resulted in the decrease of ATG5, Beclin-1 and LC3B II/I. We created oxidative stress within HEI-OC1 by H2O2, subsequently observed the formation of autophagosomes under electron microscope, so as the elevated cell apoptosis rate and weakened cell viability. MiR-130b-3p/PPARγ contributed to the premature senescence of these H2O2-induced HEI-OC1 cells. MiR-130b-3p regulated HEI-OC1 cell growth by targeting PPARγ, thus leading to ARHL.

Age standardization and time-of-day performance for the Oldenburg Sentence Test (OLSA): results from the population-based Gutenberg Health Study

PURPOSE

The Oldenburg Sentence Test (OLSA) is a German matrix test designed to determine speech recognition thresholds (SRT). It is widely used for hearing-aids and cochlear implant fitting, but an age-adjusted standard is still lacking. In addition, knowing that the ability to concentrate is an important factor in OLSA performance, we hypothesized that OLSA performance would depend on the time of day it was administered. The aim of this study was to propose an age standardization for the OLSA and to determine its diurnal performance.

METHODS

The Gutenberg Health Study is an ongoing population-based study and designed as a single-centre observational, prospective cohort study. Participants were interviewed about common otologic symptoms and tested with pure-tone audiometry and OLSA. Two groups-subjects with and without hearing loss-were established. The OLSA was performed in two runs. The SRT was evaluated for each participant. Results were characterized by age in 5-year cohorts, gender and speech recognition threshold (SRT). A time stamp with an hourly interval was also implemented.

RESULTS

The mean OLSA SRT was - 6.9 ± 1.0 dB (group 1 male) and - 7.1 ± 0.8 dB (group 1 female) showing an inverse relationship with age in the whole cohort, whereas a linear increase was observed in those without hearing loss. OLSA-SRT values increased more in males than in females with increasing age. No statistical significance was found for the diurnal performance.

CONCLUSIONS

A study with 2900 evaluable Oldenburg Sentence Tests is a novelty and representative for the population of Mainz and its surroundings. We postulate an age- and gender-standardized scale for the evaluation of the OLSA. In fact, with an intergroup standard deviation (of about 1.5 dB) compared to the age dependence of 0.7 dB/10 years, this age normalization should be considered as clinically relevant.

Hearing health survey of the population in Bangkok

In this cross-sectional random survey among Thai adults living in Bangkok, we aimed to identify the prevalence of hearing problems and examine their relationship with individual factors. We administered a self-report questionnaire and performed pure-tone air conduction threshold audiometry. A total of 2463 participants (1728 female individuals) aged 15-96 years were included. The hearing loss prevalence was 53.02% and increased with age. The prevalence of a moderate or greater degree of hearing impairment was 2.8%. Participants aged 65 years and over had 8.56 and 6.79 times greater hearing loss and hearing impairment than younger participants, respectively. Male participants were twice as likely to have hearing loss and hearing impairment as female individuals. Participants with higher education levels showed less likelihood of having hearing loss and hearing impairment than those with no or a primary school education. Participants who ever worked under conditions with loud noise for > 8 h per day had 1.56 times greater hearing loss than those without such exposure. An inconsistent correlation was found between hearing loss, hearing impairment and noncommunicable diseases (diabetes, hypertension, and obesity). Although most participants had mild hearing loss, appropriate care and monitoring are necessary to prevent further loss in such individuals. The questionnaire-based survey found only people with hearing problems that affect daily communication.

Clinical characteristics of the "Gap" between the prevalence and incidence of hearing loss using National Health Insurance Service data

OBJECTIVES

Hearing loss is the inability to hear speech or sounds well, owing to a number of causes. This study aimed to simultaneously determine the prevalence, incidence, and the Gap between them in hearing loss in South Korean patients at the same point in time as well as to identify patients who have not recovered from hearing loss.

METHODS

We examined the prevalence and incidence of patients diagnosed with hearing loss in the National Health Insurance Service database over an 11-year period from 2010 to 2020. The difference between the prevalence and the incidence was defined in this study as the term "Gap". Gap is the number of patients converted into the number of patients per 100,000 people by subtracting the incidence from the prevalence. Clinical characteristics such as sex and age per 100,000 individuals were examined.

RESULTS

As of 2020, the domestic prevalence obtained in this study was 1.84%, increasing annually, and the prevalence increased with age to 4.10% among those over 60. The domestic incidence was 1.57%, increasing annually, and the incidence increased with age to 3.36% for those over 60s. The Gap was 0.27%, showing a steady increase from 2011 to 2020 with a corresponding increase in insurance benefit expenses.

CONCLUSION

To fully understand the burden of hearing loss and develop effective prevention and treatment strategies, it is important to measure the Gap between its prevalence and incidence. This Gap means a lot because hearing loss is an irreversible disease. Gap represents patients who have already been diagnosed with hearing loss and are being diagnosed every year, indicating that the number of patients who do not recover is increasing. In other words, the increase in Gap meant that there were many patients who constantly visited the hospital for diagnosis of hearing loss.

The Effect of Rivaroxaban in the Complementary Therapy of Sudden Sensorineural Hearing Loss

Background

Due to the importance of sudden sensorineural hearing loss (SSNHL) and the possible role of blood coagulation in its mechanism and the likely therapeutic effect of anticoagulants and also the lack of studies in this field, this study aimed to evaluate the effect of rivaroxaban (RXA) in the treatment of this disease.

Materials and Methods

The present double-blind randomized clinical trial study was performed on 34 patients with SSNHL. Patients were randomly divided into two groups. In the first group, in addition to corticosteroid therapy (CST), RXA 10 mg tablets were used daily for 10 days (RXA group), and in the second group, only CST (CST group) treatment was prescribed. Hearing recovery was then assessed and recorded according to the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) criteria.

Results

This study showed that the grade of hearing recovery in the RXA group (58.8%) was higher than the CST group (47.1%), but this difference was not significant (P value >0.05). Also, RXA treatment increased the odds of hearing recovery, and this difference was not statistically significant (odd ratio (95% confidence interval)(OR (95% CI): 2.327 (0.180-18.082); P value = 0.518). In contrast, delay to treatment, more increased PTA (pure tone average (PTA)), and having vertigo reduced the odds of hearing recovery by 0.138-, 0.019-, and 0.069-fold, respectively (P value <0.05).

Conclusion

According to the results of this study, although the percentage of hearing recovery was higher in the RXA group, in general, the results of the two treatments were not significantly different.

[How Working Memory Supports Language Comprehension after Cochlear Implantation]

Language comprehension in challenging conditions requires the integration of multimodal information. Necessary resources are provided by the working memory. We discuss how adult cochlear implant users benefit from auditory-cognitive training during their rehabilitation process. Working memory capacity highly impacts language comprehension whenever listening effort is increased. Since CI users may have trouble to recover the phonological structure from the speech signal, working memory is required to provide necessary resources to disambiguate multiple interpretation options. However, either due to their hearing biography or due to their advanced age, CI user often show reduced working memory capacities. Previous studies with hearing-impaired adults provide evidence for the potential of combined auditory-cognitive training during the rehabilitation process of CI users.

A Chemical Chaperone Restores Connexin 26 Mutant Activity

Mutations in connexin 26 (Cx26) cause hearing disorders of a varying degree. Herein, to identify compounds capable of restoring the function of mutated Cx26, a novel miniaturized microarray-based screening system was developed to perform an optical assay of Cx26 functionality. These molecules were identified through a viability assay using HeLa cells expressing wild-type (WT) Cx26, which exhibited sensitivity toward the HSP90 inhibitor radicicol in the submicromolar concentration range. Open Cx26 hemichannels are assumed to mediate the passage of molecules up to 1000 Da in size. Thus, by releasing radicicol, WT Cx26 active hemichannels in HeLa cells contribute to a higher survival rate and lower cell viability when Cx26 is mutated. HeLa cells expressing Cx26 mutations exhibited reduced viability in the presence of radicicol, such as the mutants F161S or R184P. Next, molecules exhibiting chemical chaperoning activity, suspected of restoring channel function, were assessed regarding whether they induced superior sensitivity toward radicicol and increased HeLa cell viability. Through a viability assay and microarray-based flux assay that uses Lucifer yellow in HeLa cells, compounds 3 and 8 were identified to restore mutant functionality. Furthermore, thermophoresis experiments revealed that only 3 (VRT-534) exhibited dose-responsive binding to recombinant WT Cx26 and mutant Cx26K188N with half maximal effective concentration values of 19 and ∼5 μM, respectively. The findings of this study reveal that repurposing compounds already being used to treat other diseases, such as cystic fibrosis, in combination with functional bioassays and binding tests can help identify novel potential candidates that can be used to treat hearing disorders.

Impact of Hearing Aids on Progression of Cognitive Decline, Depression, and Quality of Life Among People with Cognitive Impairment and Dementia

BACKGROUND

Hearing loss is common in people with dementia (PwD) and a modifiable risk factor for cognitive decline. Recent studies revealed that hearing loss could cause social isolation and depression, which is associated with health-related quality of life (HRQoL). However, there is a lack of knowledge about the impact of the utilization of hearing aids on these outcomes.

OBJECTIVE

To assess whether hearing aids use might be positively associated with the progression of cognitive function, depression, and HRQoL among PwD.

METHODS

We analyzed two-year follow-up data from 258 PwD (≥70 years, living at home). Cognitive decline was measured with Mini-Mental Status Examination (MMSE), depression using Geriatric Depression Scale (GDS), and HRQoL with Quality of Life in Alzheimer's Disease Scale (QoL-AD). The impact of hearing aid utilization on the progression of outcomes was assessed using multivariate regression models.

RESULTS

123 patients had hearing loss (47.7%), from which n = 54 (43.9%) used hearing aids. Patients with hearing loss were older and had a lower HRQoL than those without hearing loss. Use of hearing aids in patients with hearing loss was associated with a lower increase in symptoms (b = -0.74, CI95 -1.46 --0.01, p = 0.047) over time as compared to those not using hearing aids. There was no effect on PwD's cognition, and the association with higher HRQoL was significant after one, but not consistently over two years.

CONCLUSION

Early detection and intervention of presbycusis using hearing aids might improve mental health and HRQoL in dementia.

Combined treatment of retinoic acid with olfactory ensheathing cells protect gentamicin-induced SGNs damage in the rat cochlea in vitro

Hearing is mainly dependent on the function of hair cells (HCs) and spiral ganglion neurons (SGNs) which damage or loss of them leads to irreversible hearing loss. Olfactory ensheathing cells (OECs) are specialized glia that forms the fascicles of the olfactory nerve by surrounding the olfactory sensory axons. The OECs, as a regenerating part of the nervous system, play a supporting function in axonal regeneration and express a wide range of growth factors. In addition, retinoic acid (RA) enhances the proliferation and differentiation of these cells into the nerve. In the present study, we co-cultured human OECs (hOECs) with cochlear SGNs in order to determine whether hOECs and RA co-treatment can protect the repair process in gentamycin-induced SGNs damage in vitro. For this purpose, cochlear cultures were prepared from P4 Wistar rats, which were randomly appointed to four groups: normal cultivated SGNs (Control), gentamicin-lesioned SGNs culture (Gent), gentamicin-lesioned SGNs culture treated with OECs (Gent + OECs) and gentamicin-lesioned SGNs culture co-treated with OECs and RA (Gent + OEC& RA). The expression of a specific protein in SGNs was examined using immunohistochemical and Western blotting technique. TUNEl staining was used to detect cell apoptosis. Here, we revealed that combined treatment of OECs and RA protect synapsin and Tuj-1 expression in the lesioned SGNs and attenuate cell apoptosis. These findings suggest that RA co-treatment can enhance efficiency of OECs in repair of SGNs damage induced by ototoxic drug.

Age-Related Decline of Speech Perception

Hearing loss is one of the most common disorders worldwide. It affects communicative abilities in all age groups. However, it is well known that elderly people suffer more frequently from hearing loss. Two different model approaches were employed: A generalised linear model and a random forest regression model were used to quantify the relationship between pure-tone hearing loss, age, and speech perception. Both models were applied to a large clinical data set of 19,801 ears, covering all degrees of hearing loss. They allow the estimation of age-related decline in speech recognition for different types of audiograms. Our results show that speech scores depend on the specific type of hearing loss and life decade. We found age effects for all degrees of hearing loss. A deterioration in speech recognition of up to 25 percentage points across the whole life span was observed for constant pure-tone thresholds. The largest decrease was 10 percentage points per life decade. This age-related decline in speech recognition cannot be explained by elevated hearing thresholds as measured by pure-tone audiometry.

Cognitive decline, sensory impairment, and the use of audio-visual aids by long-term care facility residents

BACKGROUND

Hearing and vision impairments and the use of audio-visual aids are associated with cognitive decline in community-dwelling older people, but effects in long-term care facilities (LFCF) are unclear. We hypothesize that visual and hearing impairment are associated with cognitive decline and these relationships are mediated by using visual and hearing aids.

METHODS

Secondary data analysis of a longitudinal study was conducted in the 7 government-subsidized LTCF operated by one of the largest non-governmental organizations in Hong Kong using data between 2005 and 2016. Eligible residents were ≥ 60 years of age without severe cognitive impairment at baseline who had stayed in the facilities for more than 3 years. All variables were measured by using the Minimum Data Set-Resident Assessment Instrument Version 2.0, Hong Kong version. The outcome was cognitive decline. Predictors were visual and hearing impairments. Mediators were the use of visual and hearing aids. General linear models were employed to test the hypotheses.

RESULTS

Results for 2,233 residents were analyzed, with a mean age of 82.1 ± 8.2 years and a mean follow-up period of 4.4 ± 0.8 years. Results showed that those who had visual impairment (p = 0.004) and hearing impairments (p = 0.022) had a higher risk of cognitive decline. Using hearing aids (coefficient = 0.0186, p < 0.05) positively mediates the effect of hearing impairment on cognitive decline. Using visual aids (coefficient = -0.0881, p < 0.05) negatively mediates the effects of visual impairment on cognitive decline.

CONCLUSION

In LTCF, hearing and visual impairments are associated with a higher risk of cognitive decline. Hearing aids often-users were associated with a higher risk of cognitive decline. LTCF residents with visual impairment did not use visual aids. Use of visual aids demonstrated potential effects in slowing cognitive decline. A future study with a larger and more diverse sample with attention to quality of devices is proposed to confirm its effects.

Wirksamkeit der Hörgeräteversorgung bei hochgradigem Hörverlust

Hintergrund

In der Praxis liegt das unilaterale Einsilberverstehen mit Hörgerät bei 65 dB SPL (EV₆₅(HG)) häufig unter dem maximalen Einsilberverstehen aus dem Sprachaudiogramm (mEV), insbesondere bei Hörgeräteträgern mit hochgradigem Hörverlust. Diese Arbeit zielte darauf ab, den Wirkungsgrad Q der Hörgeräteversorgung, den Quotienten aus EV₆₅(HG) und mEV, bei Hörgeräteträgern mit hochgradigem bis an Taubheit grenzendem Hörverlust zu untersuchen.

Material und Methoden

Es wurden Daten aus In-situ-Messungen, dem Reinton- und Sprachaudiogramm und dem Sprachverstehen mit und ohne Hörgerät von 93 Ohren von 64 Patienten ausgewertet. Die Patienten stellten sich im Jahr 2019 für eine Hörgerätekontrolle in unserem Hörzentrum vor. Es wurden die Abweichung der in-situ gemessenen frequenzabhängigen Ausgangspegelwerte von den Zielvorgaben der präskriptiven Anpassformeln NAL-NL2 und DSL v5.0 analysiert. Für die Parameter EV₆₅(HG) und Q wurden jeweils die Spearman-Korrelationskoeffizienten für den Sprachverständlichkeitsindex (SII) berechnet.

Ergebnisse

Bei mehr als 67 % der Hörgeräteeinstellungen stimmten die Ausgangspegelwerte mit den Zielkurven für NAL-NL2 oder DSL v5.0 im Bereich von ±5 dB für Frequenzen von 0,5 bis 4 kHz für 65 dB SPL überein. Trotzdem wurde das mEV mit Hörgerät bei 65 dB SPL nicht erreicht (mittlere Abweichungen: 34,4 %). EV₆₅(HG) und Q waren jedoch am besten, wenn Zielwerte für DSL v5.0 bei 65 dB SPL erreicht wurden, was mit einem höheren SII einhergeht.

Schlussfolgerung

Für Hörgeräteträger mit hochgradigem bis an Taubheit grenzendem Hörverlust führen die Anpassformeln NAL-NL2 und DSL v5.0 nicht zu einer solchen Verstärkung, dass bei Alltagssprache von 65 dB SPL das mEV erreicht wird. Es bleibt zu untersuchen, ob alternative Präskriptionen mit besserer Hörbarkeit für Eingangspegel von 50 und 65 dB SPL den Wirkungsgrad der Hörgeräteversorgung verbessern könnten.

[Vocal tract discomfort and wellbeing of caregivers for the elderly during the pandemic]

BACKGROUND

During the Sars-CoV2-pandemic, people working in healthcare such as caregives for the elderly face additional burden, e.g. by the use of face masks.

METHODS

In a prospective study, the emotional and physical wellbeing as well as the vocal tract discomfort of caregivers of two municipal homes for the elderly were assessed by questionnaires, the Mini-SCL and the Vocal Tract Discomfort Scale (VTDS), and one on personal data (sex, age, lung disease, previous SARS-CoV2-infection) and on voice symptoms.

RESULTS

67% of the questionnaires were answered by 56 women and 11 men aged 45.2 ± 11.5. In the Mini-SCL, increased scores were found in depression in 23.8%, anxiety in 49.3%, somatization in 55.2% and in the global score in 44.7%. 52%. showed increased scores in the VTDS Significant correlations were found in between the subscales of the Mini-SCL and the VTDS as well as to dysphonia symptoms.

DISCUSSION

Psychological problems, somatization and vocal tract discomfort is more frequently reported by caregivers for the elderly than in the normal population. The VTDS, voice symptoms and the Mini-SCL scales are significantly related. Training on vocal hygiene should be included in workplace health promotion during the pandemic.

Effects of mild-to-moderate sensorineural hearing loss and signal amplification on vocal emotion recognition in middle-aged–older individuals

Previous research has shown deficits in vocal emotion recognition in sub-populations of individuals with hearing loss, making this a high priority research topic. However, previous research has only examined vocal emotion recognition using verbal material, in which emotions are expressed through emotional prosody. There is evidence that older individuals with hearing loss suffer from deficits in general prosody recognition, not specific to emotional prosody. No study has examined the recognition of non-verbal vocalization, which constitutes another important source for the vocal communication of emotions. It might be the case that individuals with hearing loss have specific difficulties in recognizing emotions expressed through prosody in speech, but not non-verbal vocalizations. We aim to examine whether vocal emotion recognition difficulties in middle- aged-to older individuals with sensorineural mild-moderate hearing loss are better explained by deficits in vocal emotion recognition specifically, or deficits in prosody recognition generally by including both sentences and non-verbal expressions. Furthermore a, some of the studies which have concluded that individuals with mild-moderate hearing loss have deficits in vocal emotion recognition ability have also found that the use of hearing aids does not improve recognition accuracy in this group. We aim to examine the effects of linear amplification and audibility on the recognition of different emotions expressed both verbally and non-verbally. Besides examining accuracy for different emotions we will also look at patterns of confusion (which specific emotions are mistaken for other specific emotion and at which rates) during both amplified and non-amplified listening, and we will analyze all material acoustically and relate the acoustic content to performance. Together these analyses will provide clues to effects of amplification on the perception of different emotions. For these purposes, a total of 70 middle-aged-older individuals, half with mild-moderate hearing loss and half with normal hearing will perform a computerized forced-choice vocal emotion recognition task with and without amplification.

Hearing Loss and Its Burden of Disease in a Large German Cohort-Hearing Loss in Germany

OBJECTIVES/HYPOTHESIS

Hearing loss is the most common sensory impairment worldwide. It restricts patients in many aspects of their daily lives and can lead to social exclusion. Understanding this burden is a mandatory requirement for the care of those affected. Therefore, the aim of this study was to estimate the burden of hearing loss in a large German cohort.

STUDY DESIGN

Cohort study.

METHODS

The Gutenberg Health Study is designed as a single-center, prospective, and observational cohort study and representative for the city of Mainz, Germany, with its district. Participants were interviewed concerning common otologic symptoms and tested by pure-tone audiometry. The primary outcome was hearing impairment stratified by age and sex. The prevalence of tinnitus was estimated for a subcohort to calculate disability-adjusted life years (DALYs). All results were weighted by the European Standard Population (ESP) 2013.

RESULTS

A total of 5,024 participants (mean age: 61.2 years, 2,591 men and 2,433 women) were included in the study. Hearing impairment showed the following prevalence: 28.2% (95% confidence interval [CI], 26.9%-29.4%) mild impairment, 10.1% (95% CI, 9.3%-11.0%) moderate impairment, 2.3% (95% CI, 1.9%-2.7%) moderately severe impairment, 0.2% (95% CI, 0.1%-0.4%) severe impairment, 0% (95% CI, 0.0%-0.1%) profound impairment, and 0.1% (95% CI, 0.0%-0.2%) complete impairment. Weighted for the ESP 2013 (all ages), hearing impairment across all levels (with/without tinnitus) causes a total of 2,118.97 DALYs per 100,000.

CONCLUSION

With 40.9% affected, the hearing loss represents a relevant burden of the German population. Understanding this will provide the basis for future guidelines on how to care for these patients.

LEVEL OF EVIDENCE

2 Laryngoscope, 2021.

Hearing loss among elderly people and access to hearing aids: a cross-sectional study from a rural area in Germany

PURPOSE

Hearing loss is common and associated with reduced quality of life, particularly among elderly people. However, many patients do not use hearing aids. We evaluated the use of hearing aids among people with hearing loss by health services availability near their residence in a rural area in the state of Brandenburg, Germany.

METHODS

Audiometry was performed in a convenience sample of subjects in ten towns and hearing loss was determined, defined as a threshold of ≥ 30 dB in at least one ear and at least one of the frequencies 0.5, 1.0, 2.0 and 4.0 kHz. For each participant, age and gender were collected and whether or not hearing aids were available.

RESULTS

Among 186 persons with an average age of 74 years (interquartile range 71-81), 97% had hearing loss [95% confidence interval (CI) 95-100]. Among 121 patients with hearing loss who reported whether or not they have a hearing aid, 93 had no hearing aid (77%, 95% CI 69-84). The proportion of hearing-impaired persons who do not have a hearing aid significantly increased with the absence of a hearing aid specialist or ear nose throat (ENT) physician or both in the town where the tests were performed (p trend = 0.001).

CONCLUSION

Hearing loss is common among elderly people in the study area and many people in rural areas in Germany may not be properly supplied with hearing aids due to lack of hearing aid specialists and/or ENT physicians close to their residence. Interventions to improve this situation are urgently required.

Diagnostic Yield of Targeted Hearing Loss Gene Panel Sequencing in a Large German Cohort With a Balanced Age Distribution from a Single Diagnostic Center: An Eight-year Study

Objectives:

Hereditary hearing loss exhibits high degrees of genetic and clinical heterogeneity. To elucidate the population-specific and age-related genetic and clinical spectra of hereditary hearing loss, we investigated the sequencing data of causally associated hearing loss genes in a large cohort of hearing-impaired probands with a balanced age distribution from a single center in Southwest Germany.

Design:

Genetic testing was applied to 305 hearing-impaired probands/families with a suspected genetic hearing loss etiology and a balanced age distribution over a period of 8 years (2011–2018). These individuals were representative of the regional population according to age and sex distributions. The genetic testing workflow consisted of single-gene screening (n = 21) and custom-designed hearing loss gene panel sequencing (n = 284) targeting known nonsyndromic and syndromic hearing loss genes in a diagnostic setup. Retrospective reanalysis of sequencing data was conducted by applying the current American College of Medical Genetics and Genomics/Association for Molecular Pathology guidelines.

Results:

A genetic diagnosis was established for 75 (25%) of the probands that involved 75 causal variants in 35 genes, including 16 novel causal variants and 9 medically significant variant reclassifications. Nearly half of the solved cases (47%; n = 35) were related to variants in the five most frequently affected genes: GJB2 (25%), MYO15A, WFS1, SLC26A4, and COL11A1 (all 5%). Nearly one-quarter of the cases (23%; n = 17) were associated with variants in seven additional genes (TMPRSS3, COL4A3, LOXHD1, EDNRB, MYO6, TECTA, and USH2A). The remaining one-third of single cases (33%; n = 25) were linked to variants in 25 distinct genes. Diagnostic rates and gene distribution were highly dependent on phenotypic characteristics. A positive family history of autosomal-recessive inheritance in combination with early onset and higher grades of hearing loss significantly increased the solve rate up to 60%, while late onset and lower grades of hearing loss yielded significantly fewer diagnoses. Regarding genetic diagnoses, autosomal-dominant genes accounted for 37%, autosomal-recessive genes for 60%, and X-linked genes for 3% of the solved cases. Syndromic/nonsyndromic hearing loss mimic genes were affected in 27% of the genetic diagnoses.

Conclusions:

The genetic epidemiology of the largest German cohort subjected to comprehensive targeted sequencing for hereditary hearing loss to date revealed broad causal gene and variant spectra in this population. Targeted hearing loss gene panel analysis proved to be an effective tool for ensuring an appropriate diagnostic yield in a routine clinical setting including the identification of novel variants and medically significant reclassifications. Solve rates were highly sensitive to phenotypic characteristics. The unique population-adapted and balanced age distribution of the cohort favoring late hearing loss onset uncovered a markedly large contribution of autosomal-dominant genes to the diagnoses which may be a representative for other age balanced cohorts in other populations.

Self-reported hearing difficulty in workers exposed to industrial dust in southern Brazil

PURPOSE

To investigate the association between self-reported hearing difficulties and occupational exposure to industrial dust in workers in southern Brazil.

METHODS

This is a cross-sectional analytical study conducted with data from the National Health Survey (Pesquisa Nacional de Saúde, 2013). The dependent variable was self-reported hearing impairment, and the primary independent variable was occupational exposure to industrial dust. The covariables were: sex, skin color, age in complete years, exposure to noise, and exposure to chemical substances. The variables of occupational exposure to noise and chemical substances were used as adjustment variables (confounding variables), and the analyses were stratified per state (Santa Catarina, Paraná, and Rio Grande do Sul) to verify the difference in magnitude results per region. For the crude and adjusted analysis, the odds ratio (OR) was used as a measure of association, estimated through the logistic regression analysis. The data were analyzed through the software Stata, version 14.

RESULTS

Regarding the main exposure, 10.1% of the sample (n = 490) reported being exposed to industrial dust in an occupational environment, while 7.0% reported hearing impairment. In the final analysis, workers exposed to industrial dust were 1.77 times more likely to report hearing impairment when compared to individuals not exposed to this agent.

CONCLUSION

There was an association between hearing impairment and exposure to industrial dust in workers in the southern region of Brazil.

Environmental Noise Classification with Inception-Dense Blocks for Hearing Aids

Hearing aids are increasingly essential for people with hearing loss. For this purpose, environmental noise estimation and classification are some of the required technologies. However, some noise classifiers utilize multiple audio features, which cause intense computation. In addition, such noise classifiers employ inputs of different time lengths, which may affect classification performance. Thus, this paper proposes a model architecture for noise classification, and performs experiments with three different audio segment time lengths. The proposed model attains fewer floating-point operations and parameters by utilizing the log-scaled mel-spectrogram as an input feature. The proposed models are evaluated with classification accuracy, computational complexity, trainable parameters, and inference time on the UrbanSound8k dataset and HANS dataset. The experimental results showed that the proposed model outperforms other models on two datasets. Furthermore, compared with other models, the proposed model reduces model complexity and inference time while maintaining classification accuracy. As a result, the proposed noise classification for hearing aids offers less computational complexity without compromising performance.

Vocal tract discomfort in caregivers for the elderly during an interval of the COVID-19 pandemic

BACKGROUND

During the coronavirus disease 2019 (COVID-19) pandemic, professional caregivers caring for the elderly may experience more vocal tract problems in addition to regular high vocal demands while wearing face masks/coverings.

METHODS AND PARTICIPANTS

Vocal tract discomfort (VTD) was assessed in 64 caregivers in one home for the elderly (64% participation rate) in June 2020 using the German version of the VTD scale.

RESULTS

More than one-half of the participating caregivers experienced VTD, described mostly as dryness, irritability, and tightness. Approximately, 80% reported that sensations were not perceived before enhanced infection prevention standards were implemented.

CONCLUSIONS

Among caregivers caring for the elderly during the COVID-19 pandemic, special care should be focused on the voice and vocal tract well-being.

Noise Damage Accelerates Auditory Aging and Tinnitus: A Canadian Population-Based Study

OBJECTIVE

Age-related hearing loss (ARHL) is the third most challenging disability in older adults. Noise is a known modifiable risk factor of ARHL, which can drive adverse health effects. Few large-scale studies, however, have shown how chronic noise exposure (CNE) impacts the progression of ARHL and tinnitus.

STUDY DESIGN

Retrospective large-scale study.

SETTING

Audiology clinical practice.

PATIENTS

In this study, 928 individuals aged 30-100 years without (n=497) or with the experience of CNE (n=431) were compared in their hearing assessments and tinnitus. In order to only investigate the impact of CNE on ARHL and tinnitus, people with other risk factors of hearing loss were excluded from the study.

INTERVENTION

Diagnostic.

MAIN OUTCOME MEASURES

Noise damage was associated with a greater ARHL per age decades (pure-tone average(PTA)0.5-4kHz alterations 19.6-70.8 dB vs. 8.0-63.2 dB, ≤0.001), an acceleration of developing a significant ARHL at least by two decades (PTA0.5-4kHz 33.4 dB at 50-59yr vs. 28.2 dB at 30-39yr, ≤0.001), and an increased loss of word recognition scores (total average 84.7% vs. 80.0%, ≤0.001). Significant noise-associated growth in the prevalence of tinnitus also was shown, including more than a triple prevalence for constant tinnitus (28.10% vs. 8.85%, ≤0.001) and near to a double prevalence for intermittent tinnitus (19.10% vs. 11.10%, ≤0.001). Noise also resulted in the elevation of the static compliance of the tympanic membrane throughout age (total average 0.61 vs. 0.85 mmho, ≤0.001).

CONCLUSIONS

Our findings emphasize the significant contribution of CNE in auditory aging and the precipitation of both ARHL and tinnitus.

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.

Influence of the basilar membrane shape and mechanical properties in the cochlear response: A numerical study

Hearing impairment is one of the most common health disorders, affecting individuals of all ages, reducing considerably their quality of life. At present, it is known that during an acoustic stimulation a travelling wave is developed inside the cochlea. Existing mathematical and numerical models available in the literature try to describe the shape of this travelling wave, the majority of them present a set of approaches based on some limitations either or both of the mechanical properties used and the geometrical description of the realistic representation. The present numerical study highlights the distinctions of using a spiral model of the cochlea, by comparing the obtained results with a straight, or simplified model. The influence of the implantation of transversely isotropic mechanical models was also studied, by comparing the basilar membrane with isotropic and transversely isotropic mechanical properties. Values of the root mean square error calculated for all models show a greater proximity of the cochlear mapping to the Greenwood function when the basilar membrane is assumed with transversely isotropic mechanical properties for both straight and spiral model. The root-mean square errors calculated were: 2.05, 1.70, 2.72, 2.08 mm, for the straight-isotropic, straight-transversely isotropic, spiral-isotropic and spiral-transversely isotropic model, respectively.

Cochlear Implantation

BACKGROUND

Hearing impairment that is too severe to be adequately treated with conventional hearing aids can lead, in children, to severe developmental disturbances of hearing and language, and, in adults, to communicative and social deprivation. Recent advances in medical device technology and in microsurgical techniques have led to an expansion of the indications for cochlear implantation (CI) for adults with progressive hearing loss in older age, and to a restructuring of the process of care for these patients in Germany.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed, as well as on the CI guidelines and CI "white book" of the German Society of Otolaryngology and Head and Neck Surgery.

RESULTS

Early and accurate diagnosis is crucial for the successful auditory rehabilitation of high-grade hearing impairment. In children, a key role is played by newborn auditory screening, which is mandatory in Germany and enables the provision of a CI in the first year of life when necessary. 86% of the children receiving a CI achieve linguistic comprehension of fluently spoken sentences. For adults, positive prognostic factors for hearing after the provision of a CI include a highly motivated patient, "postlingual" onset of the hearing impairment (i.e., after the acquisition of language), and a brief duration of deafness. Auditory rehabilitation is associated with significant improvement, not just of hearing and of the comprehension of spoken language, but also of quality of life, particularly in elderly patients. For patients of any age with bilateral hearing loss, CIs should be provided on both sides, if possible. The more common complications of the procedure, with a probability of 2-4% each, are technical implant defects, dizziness, and wound-healing disturbances.

CONCLUSION

Cochlear implantation, performed in specialized centers, is a safe and reliable technique and regularly enables the successful rehabilitation of hearing in both children and adults.

Genome-wide association study identifies 7q11.22 and 7q36.3 associated with noise-induced hearing loss among Chinese population

Noise-induced hearing loss (NIHL) seriously affects the life quality of humans and causes huge economic losses to society. To identify novel genetic loci involved in NIHL, we conducted a genome-wide association study (GWAS) for this symptom in Chinese populations. GWAS scan was performed in 89 NIHL subjects (cases) and 209 subjects with normal hearing who have been exposed to a similar noise environment (controls), followed by a replication study consisting of 53 cases and 360 controls. We identified that four candidate pathways were nominally significantly associated with NIHL, including the Erbb, Wnt, hedgehog and intraflagellar transport pathways. In addition, two novel index single-nucleotide polymorphisms, rs35075890 in the intron of AUTS2 gene at 7q11.22 (combined P = 1.3 × 10^-6 ) and rs10081191 in the intron of PTPRN2 gene at 7q36.3 (combined P = 2.1 × 10^-6 ), were significantly associated with NIHL. Furthermore, the expression quantitative trait loci analyses revealed that in brain tissues, the genotypes of rs35075890 are significantly associated with the expression levels of AUTS2, and the genotypes of rs10081191 are significantly associated with the expressions of PTPRN2 and WDR60. In conclusion, our findings highlight two novel loci at 7q11.22 and 7q36.3 conferring susceptibility to NIHL.

Pilotstudie zum Hörscreening mit dem Mini-Audio-Test (MAT)

Hintergrund Es gibt Hinweise, dass eine unbehandelte Schwerhörigkeit in der 2. Lebenshälfte das Risiko, an einer Demenz oder Depression zu erkranken, einen kognitiven Leistungsverlust zu erleiden, zu stürzen oder allgemein hilfsbedürftig zu werden, erhöht. Ein Großteil der Betroffenen ist nicht adäquat, z. B. mit Hörgeräten, behandelt. Der Mini-Audio-Test (MAT) ist ein evaluierter Fragebogen, der eine bisher nicht bekannte Schwerhörigkeit aufdecken kann. Mit dieser Studie sollte die Einsatzfähigkeit des MAT in einer repräsentativen Stichprobe der erwachsenen Bevölkerung getestet werden.

Methoden Im Frühjahr 2019 wurden insgesamt 123 Personen im Rahmen einer repräsentativen Befragung u. a. zu ihrem Hörvermögen mittels MAT befragt. Probanden mit auffälligem MAT wurde empfohlen, sich bei einem HNO-Arzt untersuchen zu lassen. Die zugehörigen Daten wurden anonymisiert zentral erfasst und deskriptiv statistisch ausgewertet.

Ergebnisse Insgesamt waren 79 der angesprochenen Probanden im Alter von 28 bis 93 Jahren bereit, an der Befragung teilzunehmen. Von diesen haben 63 den MAT ausgefüllt, 22 davon waren bereit, sich HNO-ärztlich untersuchen zu lassen; dieses ist nur in einem Fall tatsächlich geschehen.

Diskussion Ein unspezifischer Einsatz des MAT zum Screening auf Schwerhörigkeit erscheint zum jetzigen Zeitpunkt wenig Erfolg versprechend. Sinnvoller erscheint der strukturierte Einsatz, z. B. im Rahmen eines regulären Arztbesuchs ab dem 50. Lebensjahr. Ferner sollte die Bevölkerung grundsätzlich besser über die Risiken einer unbehandelten Schwerhörigkeit aufgeklärt werden.

[Speech quality changes due to face masks]

In Arztpraxen nimmt der Infektionsschutz mittels Mund-Nasen-Maske momentan eine zentrale Rolle ein. Wenig nachgedacht wird dabei über die Folgen für die Kommunikation. Gerade schwerhörigen Patienten bereiten gedämpfte Stimmen und abgedeckte Lippen Probleme.

Hearing Impairment in Old Age

BACKGROUND

Hearing impairment associated with old age (presbycusis) is becoming more common because the population is aging.

METHODS

This review is based on publications retrieved by a selective search in Medline and Google Scholar, including individual studies, meta-analyses, guidelines, Cochrane reviews, and other reviews.

RESULTS

The cardinal symptom of presbycusis is impaired communication due to bilateral hearing impairment. Patients may be unaware of the problem for a long time because of its insidious progression. Evidence suggests that untreated hearing impair- ment in old age can have extensive adverse effects on the patient's mental, physical, and social well-being. Early detection is possible with the aid of simple diagnostic tests or suitable questionnaires. In most cases, bilateral hearing aids are an effective treatment. Surgery is rarely indicated. For patients with uni- or bilateral deafness, a cochlear implant is the treatment of choice. These treatments can improve many patients' quality of life.

CONCLUSION

The small amount of evidence that is currently available suggests that presbycusis is underdiagnosed and under- treated in Germany. Early detection by physicians of all specialties, followed in each case by a specialized differential diagnostic evaluation, is a desirable goal.

Childhood hearing impairment and its associated factors in sub-Saharan Africa in the 21st century: A systematic review and meta-analysis

Background

Childhood hearing impairment is still a significant cause of disability in the 21st century in developing countries. Particularly, the burden is more severe in sub-Saharan Africa, where the majority of children with hearing problems is living. Thre are great variations and inconsistencies of available findings conducted in sub-Saharan Africa. Hence, the aim of this review was to determine the pooled prevalence of childhood hearing impairment and its associated factors in sub-Saharan Africa.

Methods

Studies were searched from main databases (PubMed, CINAHL, and African Journals Online), Google Scholar, and other relevant sources using electronic and manual techniques. All observational studies, written in English and conducted among participants (aged less than 18 years) from 2000 to 2018, were eligible. Heterogeneity between included studies was assessed using I², and publication bias was explored using visual inspection of the funnel plot. Statistical analysis was carried out to determine pooled prevalence using Stata version 14. In addition, subgroup analysis was carried out for the normality criteria of hearing thresholds and characteristics of the study populations.

Results

The pooled prevalence of hearing impairment was 10% (95% confidence interval (CI): 9%-11%). The magnitude of hearing impairment varies with the normality criterion used. The most commonly used threshold was 25 and 30 dB hearing level. The prevalence of hearing impairment based on normality criterion (>20 dB, >25 dB, >30 dB, and >35 dB) were 17%, 19%, 2%, and 1%, respectively. While in the questionnaire-based evaluation, the prevalence was 6% (95% CI: 3%-9%). In addition, based on population characteristics, the prevalence of hearing impairment for school or community-based children was 6% (95% CI: 5%-7%) while the prevalence for children with comorbidities was 23% (95% CI: 15%-31%). Chronic suppurative otitis media, impacted cerumen, advanced stage of human immunodeficiency virus, tuberculosis infection, and age of the children were associated with hearing impairment in sub-Saharan Africa.

Conclusion

Hearing impairment in children and adolescents in sub-Saharan Africa was high, and associated with preventable and treatable risk factors.

Childhood hearing impairment and its associated factors in sub-Saharan Africa in the 21st century: A systematic review and meta-analysis

BACKGROUND

Childhood hearing impairment is still a significant cause of disability in the 21st century in developing countries. Particularly, the burden is more severe in sub-Saharan Africa, where the majority of children with hearing problems is living. Thre are great variations and inconsistencies of available findings conducted in sub-Saharan Africa. Hence, the aim of this review was to determine the pooled prevalence of childhood hearing impairment and its associated factors in sub-Saharan Africa.

METHODS

Studies were searched from main databases (PubMed, CINAHL, and African Journals Online), Google Scholar, and other relevant sources using electronic and manual techniques. All observational studies, written in English and conducted among participants (aged less than 18 years) from 2000 to 2018, were eligible. Heterogeneity between included studies was assessed using I2, and publication bias was explored using visual inspection of the funnel plot. Statistical analysis was carried out to determine pooled prevalence using Stata version 14. In addition, subgroup analysis was carried out for the normality criteria of hearing thresholds and characteristics of the study populations.

RESULTS

The pooled prevalence of hearing impairment was 10% (95% confidence interval (CI): 9%-11%). The magnitude of hearing impairment varies with the normality criterion used. The most commonly used threshold was 25 and 30 dB hearing level. The prevalence of hearing impairment based on normality criterion (>20 dB, >25 dB, >30 dB, and >35 dB) were 17%, 19%, 2%, and 1%, respectively. While in the questionnaire-based evaluation, the prevalence was 6% (95% CI: 3%-9%). In addition, based on population characteristics, the prevalence of hearing impairment for school or community-based children was 6% (95% CI: 5%-7%) while the prevalence for children with comorbidities was 23% (95% CI: 15%-31%). Chronic suppurative otitis media, impacted cerumen, advanced stage of human immunodeficiency virus, tuberculosis infection, and age of the children were associated with hearing impairment in sub-Saharan Africa.

CONCLUSION

Hearing impairment in children and adolescents in sub-Saharan Africa was high, and associated with preventable and treatable risk factors.

Preferences for Hearing Aid Attributes Among People with Moderate or Greater Hearing Loss in Rural China: A Discrete Choice Experiment

PURPOSE

Hearing loss has not received sufficient attention, especially in low- and middle-income countries where more than 80% of the people with hearing loss reside. Little is known about the preference for hearing aids among people with hearing loss in developing countries. The aim of this study is to elicit the preferences for hearing aid attributes among rural Chinese adults with moderate or greater hearing loss and examine how preferences vary across different individual socioeconomic characteristics.

PATIENTS AND METHODS

We interviewed 125 adults in two rural counties in Shandong province in China. A discrete choice experiment (DCE) with eight attributes, comprising out-of-pocket (OOP) costs, hearing aid style, effective in quiet settings and noisy settings, feedback (whistling), connectivity, water/sweat resistance and battery life, were employed to examine participants' preference for hearing aids. Mixed logit models were used for the statistical analyses.

RESULTS

While OOP costs, effectiveness in quiet settings, water/sweat resistance and battery life were significantly associated with choosing a hearing aid, rural Chinese adults with moderate or greater hearing loss valued effectiveness in noisy settings above other attributes of hearing aids, followed closely by lack of feedback. The preference of the attributes of OOP costs, in the canal hearing aids, effectiveness in noisy settings, connectivity and battery life varied across individual socioeconomic characteristics including sex, marriage, employment, income and education level.

CONCLUSION

Our study supported the view that the development of noise suppression and feedback cancellation systems remained the main challenge for the hearing aid industry. Since OOP costs were also associated with choosing a hearing aid, the policy advice is to improve reimbursements from insurance schemes and/or reduce the costs of hearing aids.

Age-related hearing loss and tinnitus, dementia risk, and auditory amplification outcomes

Age-related hearing loss (ARHL) or presbycusis, as the third leading cause of chronic disability in older adults, has been shown to be associated with predisposing cognitive impairment and dementia. Tinnitus is also a chronic auditory disorder demonstrating a growth rate with increasing age. Recent evidence stands for the link between bothersome tinnitus and impairments in various aspects of cognitive function. Both ARHL and age-related tinnitus affect mental health and contribute to developing anxiety, stress, and depression. The present review is a comprehensive multidisciplinary study on diverse interactions among ARHL, tinnitus, and cognitive decline in older adults. This review incorporates the latest evidence in prevalence and risk factors of ARHL and tinnitus, the neural substrates of tinnitus-related cognitive impairments, hypothesized mechanisms concerning the association between ARHL and increased risk of dementia, hearing amplification outcomes in cases with ARHL and cognitive decline, and preliminary findings on the link between ARHL and cognitive impairment in animal studies. Given extensive evidence that demonstrates advantages of using auditory amplification in the alleviation of hearing handicap, depression, and tinnitus, and the improvement of cognition, social communication, and quality of life, regular hearing screening programs for identification and management of midlife hearing loss and tinnitus is strongly recommended.

The Hearing Impairment Ontology: A Tool for Unifying Hearing Impairment Knowledge to Enhance Collaborative Research

Hearing impairment (HI) is a common sensory disorder that is defined as the partial or complete inability to detect sound in one or both ears. This diverse pathology is associated with a myriad of phenotypic expressions and can be non-syndromic or syndromic. HI can be caused by various genetic, environmental, and/or unknown factors. Some ontologies capture some HI forms, phenotypes, and syndromes, but there is no comprehensive knowledge portal which includes aspects specific to the HI disease state. This hampers inter-study comparability, integration, and interoperability within and across disciplines. This work describes the HI Ontology (HIO) that was developed based on the Sickle Cell Disease Ontology (SCDO) model. This is a collaboratively developed resource built around the ‘Hearing Impairment’ concept by a group of experts in different aspects of HI and ontologies. HIO is the first comprehensive, standardized, hierarchical, and logical representation of existing HI knowledge. HIO allows researchers and clinicians alike to readily access standardized HI-related knowledge in a single location and promotes collaborations and HI information sharing, including epidemiological, socio-environmental, biomedical, genetic, and phenotypic information. Furthermore, this ontology illustrates the adaptability of the SCDO framework for use in developing a disease-specific ontology.

Prevalence of hearing loss and use of hearing aids among children and adolescents in Germany: a systematic review

Background

Current data suggest that approximately 466 million people (5.0%) of the world’s population have disabling hearing loss, therefrom, 34 million children, impacting their quality of life. To provide estimates on the prevalence of hearing loss on a national level, we reviewed the epidemiological literature addressing hearing loss in children and adolescents living in Germany as an example for a Western country.

Methods

We searched Medline, Web of Science, Cochrane Library, ScienceDirect and LIVIVO to identify published data. Furthermore, we manually searched websites of relevant institutions and journals not listed in electronically and searched for ongoing studies and/or not yet published data in clinicaltrials.gov. Study selection, data extraction, and methodological assessment were carried out by two reviewers.

Results

In total, 11 reports provided data with sample sizes ranging from 310 up to more than 14 million children and adolescents. Prevalence data were collected by interviews (self-assessments), using pure-tone audiometry or the international classification of diseases (ICD-10) coding and ranged from 0.1 to 128 per 1000 children. Although the estimate of the prevalence of hearing loss goes down, when the threshold was raised, generating a comprehensive and coherent set of estimates proved challenging owing to clinical heterogeneity including variation in age, the study setting, the definition of hearing loss and the assessment method. Moreover, representativeness (external validity) was often impaired owing to estimates lacking currentness (i.e., referring to former West Germany) or selected (patient) data and may not be typical for a more general population.

Conclusions

In conclusions, this work raises public awareness of the high prevalence of hearing loss, highlights issues associated with epidemiological research and is of great importance for researcher and those who use epidemiological data to inform clinical and political decision making.