Sex differences in hearing: Probing the role of estrogen signaling

Expression profiling of cochlear genes uncovers sex-based cellular function in mouse cochleae

Sex is a pivotal biological factor that significantly impacts tissue homeostasis and disease susceptibility. In the auditory system, sex differences have been observed in cochlear physiology and responses to pathological conditions. However, the underlying molecular mechanisms responsible for these differences remain elusive. The current research explores the differences in gene expression profiles in the cochlea between male and female mice, aiming to understand the functional implication of sex-biased gene expression in each sex. Using RNA-sequencing analysis on cochlear tissues obtained from male and female mice, we identified a significant number of genes exhibiting sex-biased expression differences. While some of these differentially expressed genes are located on sex chromosomes, most are found on autosomal chromosomes. Further bioinformatic analysis revealed that these genes are involved in several key cellular functions. In males, these genes are notably linked to oxidative phosphorylation and RNA synthesis and processing, suggesting their involvement in mitochondrial energy production and regulatory control of gene expression. In contrast, sex-biased genes are associated with mechano-transduction and synaptic transmission within female cochleae. Collectively, our study provides valuable insights into the molecular differences between the sexes and emphasizes the need for future research to uncover their functional implications and relevance to auditory health and disease development.

The curvature quantification of wave I in auditory brainstem responses detects cochlear synaptopathy in human beings

PURPOSE

Patients with age-related hearing loss complain often about reduced speech perception in adverse listening environment. Studies on animals have suggested that cochlear synaptopathy may be one of the primary mechanisms responsible for this phenomenon. A decreased wave I amplitude in supra-threshold auditory brainstem response (ABR) can diagnose this pathology non-invasively. However, the interpretation of the wave I amplitude in humans remains controversial. Recent studies in mice have established a robust and reliable mathematic algorithm, i.e., curve curvature quantification, for detecting cochlear synaptopathy. This study aimed to determine whether the curve curvature has sufficient test-retest reliability to detect cochlear synaptopathy in aging humans.

METHODS

Healthy participants were recruited into this prospective study. All subjects underwent an audiogram examination with standard and extended high frequencies ranging from 0.125 to 16 kHz and an ABR with a stimulus of 80 dB nHL click. The peak amplitude, peak latency, curvature at the peak, and the area under the curve of wave I were calculated and analyzed.

RESULTS

A total of 80 individuals with normal hearing, aged 18 to 61 years, participated in this study, with a mean age of 26.4 years. Pearson correlation analysis showed a significant negative correlation between curvature and age, as well as between curvature and extended high frequency (EHF) threshold (10-16 kHz). Additionally, the same correlation was observed between age and area as well as age and EHF threshold. The model comparison demonstrated that the curvature at the peak of wave I is the best metric to correlate with EHF threshold.

CONCLUSION

The curvature at the peak of wave I is the most sensitive metric for detecting cochlear synaptopathy in humans  and may be applied in routine diagnostics to detect early degenerations of the auditory nerve.

Clinical Practice Guideline: Age-Related Hearing Loss Executive Summary

OBJECTIVE

Age-related hearing loss (ARHL) is a prevalent but often underdiagnosed and undertreated condition among individuals aged 50 and above. It is associated with various sociodemographic factors and health risks including dementia, depression, cardiovascular disease, and falls. While the causes of ARHL and its downstream effects are well defined, there is a lack of priority placed by clinicians as well as guidance regarding the identification, education, and management of this condition.

PURPOSE

The purpose of this clinical practice guideline is to identify quality improvement opportunities and provide clinicians trustworthy, evidence-based recommendations regarding the identification and management of ARHL. These opportunities are communicated through clear actionable statements with an explanation of the support in the literature, the evaluation of the quality of the evidence, and recommendations on implementation. The target patients for the guideline are any individuals aged 50 years and older. The target audience is all clinicians in all care settings. This guideline is intended to focus on evidence-based quality improvement opportunities judged most important by the Guideline Development Group (GDG). It is not intended to be a comprehensive, general guide regarding the management of ARHL. The statements in this guideline are not intended to limit or restrict care provided by clinicians based on their experience and assessment of individual patients.

ACTION STATEMENTS

The GDG made strong recommendations for the following key action statements (KASs): (KAS 4) If screening suggests hearing loss, clinicians should obtain or refer to a clinician who can obtain an audiogram. (KAS 8) Clinicians should offer, or refer to a clinician who can offer, appropriately fit amplification to patients with ARHL. (KAS 9) Clinicians should refer patients for an evaluation of cochlear implantation candidacy when patients have appropriately fit amplification and persistent hearing difficulty with poor speech understanding. The GDG made recommendations for the following KASs: (KAS 1) Clinicians should screen patients aged 50 years and older for hearing loss at the time of a health care encounter. (KAS 2) If screening suggests hearing loss, clinicians should examine the ear canal and tympanic membrane with otoscopy or refer to a clinician who can examine the ears for cerumen impaction, infection, or other abnormalities. (KAS 3) If screening suggests hearing loss, clinicians should identify sociodemographic factors and patient preferences that influence access to and utilization of hearing health care. (KAS 5) Clinicians should evaluate and treat or refer to a clinician who can evaluate and treat patients with significant asymmetric hearing loss, conductive or mixed hearing loss, or poor word recognition on diagnostic testing. (KAS 6) Clinicians should educate and counsel patients with hearing loss and their family/care partner(s) about the impact of hearing loss on their communication, safety, function, cognition, and quality of life. (KAS 7) Clinicians should counsel patients with hearing loss on communication strategies and assistive listening devices. (KAS 10) For patients with hearing loss, clinicians should assess if communication goals have been met and if there has been improvement in hearing-related quality of life at a subsequent health care encounter or within 1 year. The GDG offered the following KAS as an option: (KAS 11) Clinicians should assess hearing at least every 3 years in patients with known hearing loss or with reported concern for changes in hearing.

Sex differences in adverse events in Medicare individuals ≥ 66 years of age post glioblastoma treatment

PURPOSE

Glioblastoma (GB) is the most common primary malignant brain tumor with the highest incidence occurring in older adults with a median age at diagnosis of 64 years old. While treatment often improves survival it brings toxicities and adverse events (AE). Here we identify sex differences in treatment patterns and AE in individuals ≥ 66 years at diagnosis with GB.

METHODS

Using the SEER-Medicare dataset sex differences in adverse events were assessed using multivariable logistic regression performed to calculate the male/female odds ratio (M/F OR) and 95% confidence intervals [95% CI] of experiencing an AE adjusted for demographic variables and Elixhauser comorbidity score.

RESULTS

Males with GB were more likely to receive standard of care (SOC; Surgery with concurrent radio-chemotherapy) [20%] compared to females [17%], whereas females were more likely to receive no treatment [26%] compared to males [21%]. Females with GB receiving SOC were more likely to develop gastrointestinal disorders (M/F OR = 0.76; 95% CI,0.64-0.91, p = 0.002) or blood and lymphatic system disorders (M/F OR = 0.79; 95% CI,0.66-0.95, p = 0.012). Males with GB receiving SOC were more likely to develop cardiac disorders (M/F OR = 1.21; 95% CI,1.02-1.44, p = 0.029) and renal disorders (M/F OR = 1.65; 95% CI,1.37-2.01, p < 0.001).

CONCLUSIONS

Sex differences for individuals, 66 years and older, diagnosed with GB exist in treatment received and adverse events developed across different treatment modalities.

The multifaceted links between hearing loss and chronic kidney disease

Hearing loss affects nearly 1.6 billion people and is the third-leading cause of disability worldwide. Chronic kidney disease (CKD) is also a common condition that is associated with adverse clinical outcomes and high health-care costs. From a developmental perspective, the structures responsible for hearing have a common morphogenetic origin with the kidney, and genetic abnormalities that cause familial forms of hearing loss can also lead to kidney disease. On a cellular level, normal kidney and cochlea function both depend on cilial activities at the apical surface, and kidney tubular cells and sensory epithelial cells of the inner ear use similar transport mechanisms to modify luminal fluid. The two organs also share the same collagen IV basement membrane network. Thus, strong developmental and physiological links exist between hearing and kidney function. These theoretical considerations are supported by epidemiological data demonstrating that CKD is associated with a graded and independent excess risk of sensorineural hearing loss. In addition to developmental and physiological links between kidney and cochlear function, hearing loss in patients with CKD may be driven by specific medications or treatments, including haemodialysis. The associations between these two common conditions are not commonly appreciated, yet have important implications for research and clinical practice.

Clinical Practice Guideline: Age-Related Hearing Loss

OBJECTIVE

Age-related hearing loss (ARHL) is a prevalent but often underdiagnosed and undertreated condition among individuals aged 50 and above. It is associated with various sociodemographic factors and health risks including dementia, depression, cardiovascular disease, and falls. While the causes of ARHL and its downstream effects are well defined, there is a lack of priority placed by clinicians as well as guidance regarding the identification, education, and management of this condition.

PURPOSE

The purpose of this clinical practice guideline is to identify quality improvement opportunities and provide clinicians trustworthy, evidence-based recommendations regarding the identification and management of ARHL. These opportunities are communicated through clear actionable statements with explanation of the support in the literature, evaluation of the quality of the evidence, and recommendations on implementation. The target patients for the guideline are any individuals aged 50 years and older. The target audience is all clinicians in all care settings. This guideline is intended to focus on evidence-based quality improvement opportunities judged most important by the guideline development group (GDG). It is not intended to be a comprehensive, general guide regarding the management of ARHL. The statements in this guideline are not intended to limit or restrict care provided by clinicians based on their experience and assessment of individual patients.

ACTION STATEMENTS

The GDG made strong recommendations for the following key action statements (KASs): (KAS 4) If screening suggests hearing loss, clinicians should obtain or refer to a clinician who can obtain an audiogram. (KAS 8) Clinicians should offer, or refer to a clinician who can offer, appropriately fit amplification to patients with ARHL. (KAS 9) Clinicians should refer patients for an evaluation of cochlear implantation candidacy when patients have appropriately fit amplification and persistent hearing difficulty with poor speech understanding. The GDG made recommendations for the following KASs: (KAS 1) Clinicians should screen patients aged 50 years and older for hearing loss at the time of a health care encounter. (KAS 2) If screening suggests hearing loss, clinicians should examine the ear canal and tympanic membrane with otoscopy or refer to a clinician who can examine the ears for cerumen impaction, infection, or other abnormalities. (KAS 3) If screening suggests hearing loss, clinicians should identify sociodemographic factors and patient preferences that influence access to and utilization of hearing health care. (KAS 5) Clinicians should evaluate and treat or refer to a clinician who can evaluate and treat patients with significant asymmetric hearing loss, conductive or mixed hearing loss, or poor word recognition on diagnostic testing. (KAS 6) Clinicians should educate and counsel patients with hearing loss and their family/care partner(s) about the impact of hearing loss on their communication, safety, function, cognition, and quality of life (QOL). (KAS 7) Clinicians should counsel patients with hearing loss on communication strategies and assistive listening devices. (KAS 10) For patients with hearing loss, clinicians should assess if communication goals have been met and if there has been improvement in hearing-related QOL at a subsequent health care encounter or within 1 year. The GDG offered the following KAS as an option: (KAS 11) Clinicians should assess hearing at least every 3 years in patients with known hearing loss or with reported concern for changes in hearing.

Trends in prevalence of hearing loss in adults in the USA 1999-2018: a cross-sectional study

BACKGROUND

A better understanding of how the prevalence of hearing loss and its associated factors change over time could help in developing an appropriate program to prevent the development of hearing loss.

METHODS

Population-representative cross-sectional data from the United States National Health and Nutrition Examination Survey (NHANES) were used to estimate the trends in the prevalence of hearing loss among adults in the USA over the period 1999-2018. A total of 15,498 adult participants aged 20 years or older had complete audiometric examination data. Logistic regression was employed to evaluate the trend in hearing loss; weighted Rao-Scott χ2 tests and univariate logistic regression analyses were used to examine the association between hearing loss and relevant factors.

RESULTS

The overall hearing loss prevalence in 1999-2018 was 19.1% 19.1 (95% CI, 18.0-20.2%). The prevalence of hearing loss decreased in cycles (P for trend < 0.001). For participants aged 20-69 years, the prevalence decreased from 15.6% (95% CI, 12.9-18.4%) in 1999-2000 to 14.9% (95% CI, 13.2- 16.6%) in 2015-2016; for participants aged > 70 years the prevalence decreased from 79.9% (95% CI, 76.1-83.8%) in 2005-2006 to 64.5% (95% CI, 58.8-70.2%) in 2017-2018. Participants with hearing loss were likely to be older, male, non-Hispanic white, and to have not completed high school. Mild hearing loss was more prevalent among those aged 20-79 years; in those aged over 80 years the prevalence of moderate hearing loss exceeded that of mild loss. Among all otologically normal participants, hearing thresholds increased with age across the entire frequency range.

CONCLUSIONS

The prevalence of hearing loss in USA adults changed over the period 1999-2018. The trends observed provide valuable insight for making public health plans and allocating resources to hearing care. Further investigation is necessary to monitor hearing loss and its potential risk factors.

Sex differences in associated factors for age-related hearing loss

The prevalence and age of onset of hearing loss differ according to sex. This study aimed to identify associated factors for age-related hearing loss (ARHL) and determine whether there are differences between males and females regarding associated factors for ARHL. This cross-sectional study used data from adults who underwent medical examinations including hearing tests from 2011 to 2021. A total of 2,349 individuals were included. The study conducted sex-specific analyses using both univariate and multiple regression. Univariate analysis employed logistic regression, while multiple regression involved variable selection through the augmented backward elimination method. Separate multiple logistic regression analyses were conducted for each sex. In the univariate analysis, among males, age, underweight, alcohol consumption, weight, and height exhibited statistical significance. Among females, age, hypertension, diabetes, dyslipidemia, obesity, sarcopenia, weight, height, age at menarche, and duration of hormone exposure were found to be significant factors. However, in the multiple logistic regression model for males, underweight, and smoking emerged as significant, while in females, age, weight, obesity, and age at menarche retained their significance. We found that there are different associated factors for ARHL in each sex. Assessment and counseling for smoking, obstetric history, underweight, and obesity may be beneficial in managing patients with ARHL.

Loss of Esr1 Does Not Affect Hearing and Balance

Although estrogen affects the structure and function of the nervous system and brain and has a number of effects on cognition, its roles in the auditory and vestibular systems remain unclear. The actions of estrogen are mediated predominately through two classical nuclear estrogen receptors, estrogen receptor 1 (ESR1) and estrogen receptor 2 (ESR2). In the current study, we investigated the roles of ESR1 in normal auditory function and balance performance using 3-month-old wild-type (WT) and Esr1 knockout (KO) mice on a CBA/CaJ background, a normal-hearing strain. As expected, body weight of Esr1 KO females was lower than that of Esr1 KO males. Body weight of Esr1 KO females was higher than that of WT females, while there was no difference in body weight between WT and Esr1 KO males. Similarly, head diameter was higher in Esr1 KO vs. WT females. Contrary to our expectations, there were no differences in auditory brainstem response (ABR) thresholds, ABR waves I-V amplitudes and ABR waves I-V latencies at 8, 16, 32, and 48 kHz, distortion product otoacoustic emission (DPOAE) thresholds and amplitudes at 8, 16, and 32 kHz, and rotarod balance performance (latency to fall) between WT and Esr1 KO mice. Furthermore, there were no sex differences in ABRs, DPOAEs, and rotarod balance performance in Esr1 KO mice. Taken together, our findings show that Esr1 deficiency does not affect auditory function or balance performance in normal hearing mice, and suggest that loss of Esr1 is likely compensated by ESR2 or other estrogen receptors to maintain the structure and function of the auditory and vestibular systems under normal physiological conditions.

The human OPA1delTTAG mutation induces adult onset and progressive auditory neuropathy in mice

Dominant optic atrophy (DOA) is one of the most prevalent forms of hereditary optic neuropathies and is mainly caused by heterozygous variants in OPA1, encoding a mitochondrial dynamin-related large GTPase. The clinical spectrum of DOA has been extended to a wide variety of syndromic presentations, called DOAplus, including deafness as the main secondary symptom associated to vision impairment. To date, the pathophysiological mechanisms underlying the deafness in DOA remain unknown. To gain insights into the process leading to hearing impairment, we have analyzed the Opa1delTTAG mouse model that recapitulates the DOAplus syndrome through complementary approaches combining morpho-physiology, biochemistry, and cellular and molecular biology. We found that Opa1delTTAG mutation leads an adult-onset progressive auditory neuropathy in mice, as attested by the auditory brainstem response threshold shift over time. However, the mutant mice harbored larger otoacoustic emissions in comparison to wild-type littermates, whereas the endocochlear potential, which is a proxy for the functional state of the stria vascularis, was comparable between both genotypes. Ultrastructural examination of the mutant mice revealed a selective loss of sensory inner hair cells, together with a progressive degeneration of the axons and myelin sheaths of the afferent terminals of the spiral ganglion neurons, supporting an auditory neuropathy spectrum disorder (ANSD). Molecular assessment of cochlea demonstrated a reduction of Opa1 mRNA level by greater than 40%, supporting haploinsufficiency as the disease mechanism. In addition, we evidenced an early increase in Sirtuin 3 level and in Beclin1 activity, and subsequently an age-related mtDNA depletion, increased oxidative stress, mitophagy as well as an impaired autophagic flux. Together, these results support a novel role for OPA1 in the maintenance of inner hair cells and auditory neural structures, addressing new challenges for the exploration and treatment of OPA1-linked ANSD in patients.

The perception of ultrasonic vocalizations by laboratory mice following intense noise exposures

Noise-induced hearing loss interacts with age, sex, and listening conditions to affect individuals' perception of ecologically relevant stimuli like speech. The present experiments assessed the impact of age and sex on vocalization detection by noise-exposed mice trained to detect a downsweep or complex ultrasonic vocalization in quiet or in the presence of a noise background. Daily thresholds before and following intense noise exposure were collected longitudinally and compared across several factors. All mice, regardless of age, sex, listening condition, or stimulus type showed their poorest behavioral sensitivity immediately after the noise exposure. There were varying degrees of recovery over time and across factors. Old-aged mice had greater threshold shifts and less recovery compared to middle-aged mice. Mice had larger threshold shifts and less recovery for downsweeps than for complex vocalizations. Female mice were more sensitive, had smaller post-noise shifts, and had better recovery than males. Thresholds in noise were higher and less variable than thresholds in quiet, but there were comparable shifts and recovery. In mice, as in humans, the perception of ecologically relevant stimuli suffers after an intense noise exposure, and results differ from simple tone detection findings.

The Multi-Modal Evaluation of Sensory Sensitivity (MESSY): Assessing a commonly missed symptom of acquired brain injury

Objective: Sensory hypersensitivity is common after acquired brain injury. Since appropriate diagnostic tools are lacking, these complaints are overlooked by clinicians and available literature is limited to light and noise hypersensitivity after concussion. This study aimed to investigate the prevalence of sensory hypersensitivity in other modalities and after other types of brain injury. Method: We developed the Multi-Modal Evaluation of Sensory Sensitivity (MESSY), a patient-friendly questionnaire that assesses sensory sensitivity across multiple sensory modalities. 818 neurotypical adults (mean age = 49; 244 male) and 341 chronic acquired brain injury patients (including stroke, traumatic brain injury, and brain tumour patients) (mean age = 56; 126 male) completed the MESSY online. Results: The MESSY had a high validity and reliability in neurotypical adults. Post-injury sensory hypersensitivity (examined using open-ended questions) was reported by 76% of the stroke patients, 89% of the traumatic brain injury patients, and 82% of the brain tumour patients. These complaints occurred across all modalities with multisensory, visual, and auditory hypersensitivity being the most prevalent. Patients with post-injury sensory hypersensitivity reported a higher sensory sensitivity severity on the multiple-choice items of the MESSY as compared to neurotypical adults and acquired brain injury patients without post-injury sensory hypersensitivity (across all sensory modalities) (effect sizes (partial eta squared) ranged from .06 to .22). Conclusions: These results show that sensory hypersensitivity is prevalent after different types of acquired brain injury as well as across several sensory modalities. The MESSY can improve recognition of these symptoms and facilitate further research.

Sex differences in symptom presentation and their impact on diagnostic accuracy in Werner syndrome

AIM

Whether sex differences exist in hereditary progeroid syndromes remains unclear. In this study, we investigated sex differences in patients with Werner syndrome (WS), a model of human aging, using patient data at the time of diagnosis.

METHODS

The presence of six cardinal signs in the diagnostic criteria was retrospectively evaluated.

RESULTS

We found that the percentage of patients with all cardinal signs was higher in males than in females (54.2% vs. 21.2%). By the age of 40 years, 57.1% of male patients with WS presented with all the cardinal signs, whereas none of the female patients developed all of them. In particular, the frequency of having a high-pitched, hoarse voice, a characteristic of WS, was lower in female patients. The positive and negative predictive values for clinical diagnosis were 100% for males and females, indicating the helpfulness of diagnostic criteria regardless of sex. More female patients than male (86.7% vs. 64%) required genetic testing for their diagnosis because their clinical symptoms were insufficient, suggesting the importance of genetic testing for females even if they do not show typical symptoms of WS. Finally, the frequency of abnormal voice was lower in patients with WS harboring the c.3139-1G > C homozygous mutation.

CONCLUSION

These results indicate, for the first time, that there are sex differences in the phenotypes of hereditary progeroid syndromes. The analysis of this mechanism in this human model of aging may lead to the elucidation of sex differences in the various symptoms of normal human aging. Geriatr Gerontol Int 2024; 24: 161-167.

The validity of using a self-report single question as a means to detect hearing loss in an adolescent population

OBJECTIVE

The overall objective in the study was to compare self-reported hearing based on a single question ("how good would you currently rate your hearing?") to measure hearing loss determined by audiometry in a cohort of adolescents. Prevalence of audiometrically measured hearing loss and frequencies of self-reported poor hearing as well as factors that have an impact on self-reported hearing were examined.

DESIGN

Baseline and 5-year follow-up data of the Ohrkan study were used. Participants filled in a questionnaire and underwent audiometric measurements.

STUDY SAMPLE

Data from 979 adolescents were analysed. Participants were 54.7% female and aged between 13 and 18 years at baseline and 17-21 years at 5-yr follow-up.

RESULTS

The single question on self-reported hearing ability achieved a sensitivity of 41.9% and a positive predictive value of 7.1% at baseline. For the 5-yr follow-up, sensitivity was 40.0%, positive predictive value was 13.9%. Factors influencing self-reported poor hearing were gender, tinnitus, "muffled" ears after exposure to loud noise (e.g. after a concert) and low-frequency hearing loss.

CONCLUSIONS

The single question about hearing ability used in the Ohrkan study is not sufficient to replace audiometry to detect hearing loss as defined in the study in adolescents.

Cognitive Performance, Sociodemographic Factors, Pure-Tone Audiometry, and their Association with Speech Discrimination: A Prospective Population-Based Study of 1,061 Older Adults

OBJECTIVE

Hearing loss is increasingly recognized as a chronic disease state with important health sequelae. Although considered a central component of routine audiometric testing, the degree to which various patient factors influence speech discrimination is poorly characterized to date. The primary objective of the current work was to describe associations of cognitive performance, sociodemographic factors, and pure-tone audiometry with speech discrimination in older adults.

STUDY DESIGN

Prospective study.

SETTING

Olmsted County, Minnesota.

PATIENTS

There were 1,061 study participants 50 years or older at enrollment in the population-based Mayo Clinic Study of Aging between November 2004 and December 2019 who underwent formal audiometric and cognitive testing included in the current investigation.

MAIN OUTCOME MEASURES

The primary outcome measure was word recognition scores (WRSs; measured as <100% vs 100% as well as continuous), with pure-tone averages (PTAs; 0.5, 1, 2, and 3 kHz), age, sex, years of education, state area deprivation index (ADI) quintiles, and global cognition z scores as explanatory features.

RESULTS

The mean (SD) age among the 1,061 participants was 76 (9) years with 528 (50%) males. Participant age [OR (95% CI) for a 10-year increase of 1.8 (1.4-2.3), p < 0.001], male sex [OR = 2.6 (1.9-3.7), p < 0.001], and PTA [OR for a 10-dB hearing loss increase of 2.4 (2.1-2.8), p < 0.001] were all significantly associated with <100% WRSs, with the greatest explanatory ability attributable to the PTA. Years of education ( p = 0.9), state ADI quintile ( p = 0.6), and global cognitive performance ( p = 0.2) were not associated with WRS. The multivariable model demonstrated strong predictive ability for less than perfect WRSs, with a c index of 0.854. Similar results were seen for WRSs analyzed as continuous, with the multivariable model resulting in an R2 value of 0.433.

CONCLUSIONS

Although PTA exhibited the greatest influence on speech discrimination, advancing age and male sex both independently increased the likelihood of having worse speech discrimination among older adults, even after accounting for years of education, neighborhood-level socioeconomic disadvantage, and cognitive function. These findings help identify patient factors that can be instrumental when designing screening programs for adult-onset hearing loss.

Women with hearing loss show increased dementia risk and brain atrophy

Hearing loss is a modifiable risk factor for dementia. However, it is unknown whether risk differs by sex. Study 1 used Cox proportional hazard models to examine sex differences in the association between hearing loss (measured by speech-reception thresholds) and dementia risk. Study 2 examined how 2-year changes in hearing is associated with changes in brain volume in auditory-limbic regions. Both studies used UK Biobank data. Women with poor hearing had the greatest risk of dementia, whereas women and men with insufficient hearing were at similar risk. Men with poor hearing did not have increased risk. Presence of social isolation/depressed mood minimally contributed to dementia risk in men and women. Women, but not men, with hearing loss had greater atrophy in auditory and limbic regions compared to normal hearing women and men. Women with hearing loss show greater risk of dementia and brain atrophy, highlighting the need to examine sex-specific mechanisms.

mTORC2 regulates auditory hair cell structure and function

mTOR broadly controls cell growth, but little is known about the role of mTOR complex 2 (mTORC2) in the inner ear. To investigate the role of mTORC2 in sensory hair cells (HCs), we generated HC-specific Rictor knockout (HC-RicKO) mice. HC-RicKO mice exhibited early-onset, progressive, and profound hearing loss. Increased DPOAE thresholds indicated outer HC dysfunction. HCs are lost, but this occurs after hearing loss. Ultrastructural analysis revealed stunted and absent stereocilia in outer HCs. In inner HCs, the number of synapses was significantly decreased and the remaining synapses displayed a disrupted actin cytoskeleton and disorganized Ca2+ channels. Thus, the mTORC2 signaling pathway plays an important role in regulating auditory HC structure and function via regulation of the actin cytoskeleton. These results provide molecular insights on a central regulator of cochlear HCs and thus hearing.

Sex and Race Representation in Temporal Bone Histopathology Studies in the United States: A Systematic Review

OBJECTIVES

The author's objective was to evaluate sex and race representation in temporal bone histopathology studies.

DESIGN

PubMed, Embase, Cochrane, Web of Science, and Scopus were searched for studies written in English examining temporal bone histopathology specimens from U.S.-based institutions from January 1, 1947, to September 1, 2021. Two authors then performed "snowballing" by reviewing references from the initial search and included the studies that fulfilled the inclusion criteria. For each study, the following information was collected: publication details, study design, funding, institution from where temporal bone specimens were procured, number of study specimens, and donor demographical information.

RESULTS

The authors found that out of 300 studies, 166 (55%) report sex while only 15 (5%) reported race information. Over the past 70 years, the ratio of studies reporting sex to those that do not has increased from 1.00 to 2.19 and the number of female temporal bone histopathology subjects relative to male has increased from 0.67 to 0.75. Over 90% of studies that do report this information feature participant racial compositions that do not reflect the diversity of the U.S. population.

CONCLUSIONS

Studies of temporal bone histopathology often do not report participant sex or race. The reporting of participant sex and the inclusion of specimens from female donors have both increased over time. However, temporal bone histopathology study cohorts are not representative of the racial diversity of the U.S. population. The otolaryngology community must strive to build temporal bone histopathology libraries that are representative of the diverse U.S. population.

Prevalence and correlates of occupational noise-induced hearing loss among workers in the steel industry

BACKGROUND

The steel industry is one of the noisiest industries, which can predispose workers to hearing loss. In Egypt, the demand for steel is increasing due to the construction of new infrastructures as bridges, flyover roads, buildings, and towers; however, little is known about the prevalence of occupational noise-induced hearing loss (NIHL) among steel workers. Understanding the distribution of the affected workers is crucial for planning prevention strategies. This study aimed to estimate the prevalence of occupational NIHL among Egyptian steel workers and identify its correlates.

METHODS

This study was conducted at two steel factories in Egypt in November 2021. It involved an initial retrospective review of the factory medical records of the latest periodic medical examination conducted on workers from July to September in the year 2021 representing workers' health status in that year. Then, a case-control approach analysis was carried out. Eligible workers (n = 606) were enrolled and divided into two groups: noise-exposed workers (n = 396) and unexposed workers (n = 210). Univariate and multivariate regression analyses were performed.

RESULTS

Occupational exposure to hazardous A-weighted equivalent noise level (> 85 dB) was associated with higher hearing thresholds at all frequencies (highest at 4 kHz followed by 6 kHz), particularly in younger workers below the age of 40 years. Nearly 71% of noise-exposed workers had hearing impairment, and 47% had NIHL compared with unexposed workers (45.7% and 11.9%, respectively). The probability of NIHL in noise-exposed workers was 6.55 times higher than that in unexposed workers (OR = 6.55, 95%CI = 4.13, 10.40; p < 0.001). In noise-exposed workers, age and tinnitus were independent predictors of hearing thresholds, while tinnitus was found to be an independent predictor of NIHL after adjusting for age and job duration (OR = 2.06, 95%CI = 1.01, 4.20; p = 0.045).

CONCLUSION

Almost half of noise-exposed workers had NIHL. Tinnitus was found to be an independent predictor of NIHL. Decreasing noise exposure levels in steel plants is recommended to reduce hearing loss. Future research is required to study the effect of tinnitus on audiometry measurements among workers with NIHL.

Sex differences and the effect of female sex hormones on auditory function: a systematic review

Aims

First, to discuss sex differences in auditory function between women and men, and whether cyclic fluctuations in levels of female sex hormones (i.e., estradiol and progesterone) affect auditory function in pre-menopausal and post-menopausal women. Second, to systematically review the literature concerning the discussed patterns in order to give an overview of the methodologies used in research. Last, to identify the gap in knowledge and to make recommendations for future work.

Methods for the systematic review

Population, Exposure, Control, Outcome and Study design (PECOS) criteria were used in developing the review questions. The review protocol follows the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and was pre-registered in the Prospective Register of Systematic Reviews (PROSPERO; CRD42020201480). Data Sources: EMBASE, PubMed, MEDLINE (Ovid), PsycINFO, ComDisDome, CINAHL, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL) via Cochrane Library, and scanning reference lists of relevant studies, and internet resources (i.e., Mendeley) were used. Only studies published between 1999 and 2022, in English, or in English translation, were included. The quality of evidence was assessed using the Newcastle-Ottawa Scale (NOS).

Results

Sex differences: Women had more sensitive hearing (measured at the level of peripheral and central auditory system) than men. Cyclic fluctuations: Auditory function in women fluctuated during the menstrual cycle, while no such fluctuations in men over the same time period were reported. Hearing sensitivity improved in women during the late follicular phase, and decrease during the luteal phase, implying an effect of female sex hormones, although the specific effects of estradiol and progesterone fluctuations on the central auditory system remain unclear. Hearing sensitivity in women declined rapidly at the onset of menopause.

Conclusion

The review has shown the following. Consistent sex differences exist in auditory function across the auditory pathway with pre-menopausal women often showing better function than age-matched men. Moreover, pre-menopausal women show fluctuations in hearing function across the menstrual cycle with a better function during the peak of estradiol or when the ratio of estradiol to progesterone is high. Third, menopause marks the onset of hearing loss in women, characterized by a rapid decline in hearing sensitivity and a more pronounced loss than in age-matched men. Finally, the systematic review highlights the need for well-designed and -controlled studies to evaluate the influence of estradiol and progesterone on hearing by consistently including control groups (e.g., age-matched man), using objective tests to measure hormonal levels (e.g., in saliva or blood), and by testing participants at different points across the menstrual cycle.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020201480, identifier CRD42020201480.

“The two voices,” or more? Music and gender from myth and conquests to the neurosciences

Music is a unique phenomenon, constantly eliciting interest from a variety of viewpoints, several of which intersect the universal trait of musicality with sex/gender studies and the neurosciences. Its unparalleled power and physical, social, aesthetic, as well as cognitive, emotional and clinical ramifications make it a specially promising terrain for studies and reflections on sex and gender differences and their impact. This overview wishes to enhance awareness of such issues, also fostering an interdisciplinary exchange between the natural sciences, the humanities, and the arts. Over the centuries, different associations of music with the feminine gender have contributed to a pendulum between progressive recognition and stereotypical setbacks requiring to be overcome. Against this backdrop, music-related neurophysiological and psychological studies on sex and gender specificities are reviewed in their multiple approaches and results, exposing or questioning differences in structural, auditory, hormonal, cognitive, and behavioral areas, also in relation to abilities, treatment, and pedagogy. Thus, the bridging potential of music as universal yet diverse language, art, and practice, recommends its gender-aware integration into education, protective endeavors, and therapeutic interventions, to promote equality and well-being.

Association between Sleep Duration and Presbycusis in Korean Adults: Korea National Health and Nutrition Examination Survey

BACKGROUND

Sleep duration is associated with hearing loss, especially presbycusis, which is the most common type of hearing loss; however, there is limited evidence regarding this association among the Korean population. We aimed to determine the relationship between sleep duration and high-frequency hearing loss in Korean adults aged ≥40 years.

METHODS

We examined 5,547 Korean adults aged ≥40 years who completed audiometric tests and questionnaires regarding sleep duration during the 2010-2012 cycle of the Korea National Health and Nutrition Examination Survey. Mild presbycusis was defined as >25 decibels (dB) and <40 dB, whereas moderate-to-severe presbycusis was defined as >40 dB pure tone averages at high frequencies (3,000, 4,000, and 6,000 Hz) for both ears. Additionally, the sleep duration was divided into quartiles. Odds ratios and 95% confidence intervals were estimated using multivariable logistic regression after adjusting for covariates.

RESULTS

The prevalence of presbycusis in South Korean adults was 62.1%, of which 61.4% showed moderate to severe presbycusis. The incidence of moderate-to-severe, but not mild, presbycusis showed a significant positive correlation with sleep duration.

CONCLUSION

Our findings suggest that sleep duration is associated with the prevalence of presbycusis.

The impact of hearing loss on trajectories of depressive symptoms in married couples

Hearing loss is a prevalent chronic stressor among older adults and is associated with numerous adverse health outcomes. The life course principle of linked lives highlights that an individual's stressors can impact the health and well-being of others; however, there are limited large-scale studies examining hearing loss within marital dyads. Using 11 waves (1998-2018) of the Health and Retirement Study (n = 4881 couples), we estimate age-based mixed models to examine how 1) one's own hearing, 2) one's spouse's hearing, or 3) both spouses' hearing influence changes in depressive symptoms. For men, their wives' hearing loss, their own hearing loss, and both spouses having hearing loss are associated with increased depressive symptoms. For women, their own hearing loss and both spouses having hearing loss are associated with increased depressive symptoms, but their husbands' hearing loss is not. The connections between hearing loss and depressive symptoms within couples are a dynamic process that unfolds differently by gender over time.

Sex differences in body composition, voluntary wheel running activity, balance performance, and auditory function in CBA/CaJ mice across the lifespan

Hearing loss is the third most prevalent chronic health condition affecting older adults and age-related hearing loss (ARHL) is the most common form of hearing impairment. Significant sex differences in hearing have been documented in humans and rodents. In general, the results of these studies show that men lose their hearing more rapidly than women. However, the cellular mechanism underlying sex differences in hearing or hearing loss remains largely unknown, and to our knowledge, there is no well-established animal model for studying sex differences in hearing. In the current study, we examined sex differences in body composition, voluntary wheel running activity, balance performance, auditory function, and cochlear histology in young, middle-age, and old CBA/CaJ mice, a model of age-related hearing loss. As expected, body weight of young females was lower than that of males. Similarly, lean mass and total water mass of young, middle-age, and old females were lower than those of males. Young females showed higher voluntary wheel running activity during the dark cycle, an indicator of mobility, physical activity, and balance status, compared to males. Young females also displayed higher auditory brainstem response (ABR) wave I amplitudes at 8 kHz, wave II, III, V amplitudes at 8 and 48 kHz, and wave IV/I and V/I amplitude ratios at 48 kHz compared to males. Collectively, our findings suggest that the CBA/CaJ mouse strain is a useful model to study the cellular mechanisms underlying sex differences in physical activity and hearing.

Relationship of cardiovascular disease risk and hearing loss in a clinical population

Hearing loss has been associated with individual cardiovascular disease (CVD) risk factors and, to a lesser extent, CVD risk metrics. However, these relationships are understudied in clinical populations. We conducted a retrospective study of electronic health records to evaluate the relationship between hearing loss and CVD risk burden. Hearing loss was defined as puretone average (PTA_0.5,1,2,4) > 20 dB hearing level (HL). Optimal CVD risk was defined as nondiabetic, nonsmoking, systolic blood pressure (SBP) < 120 and diastolic (D)BP < 80 mm Hg, and total cholesterol < 180 mg/dL. Major CVD risk factors were diabetes, smoking, hypertension, and total cholesterol ≥ 240 mg/dL or statin use. We identified 6332 patients (mean age = 62.96 years; 45.5% male); 64.0% had hearing loss. Sex-stratified logistic regression adjusted for age, noise exposure, hearing aid use, and body mass index examined associations between hearing loss and CVD risk. For males, diabetes, hypertension, smoking, and ≥ 2 major CVD risk factors were associated with hearing loss. For females, diabetes, smoking, and ≥ 2 major CVD risk factors were significant risk factors. Compared to those with no CVD risk factors, there is a higher likelihood of hearing loss in patients with ≥ 2 major CVD risk factors. Future research to better understand sex dependence in the hearing loss-hypertension relationship is indicated.

Sex-Linked Biology and Gender-Related Research Is Essential to Advancing Hearing Health

There is robust evidence that sex (biological) and gender (behavioral/social) differences influence hearing loss risk and outcomes. These differences are noted for animals and humans-in the occurrence of hearing loss, hearing loss progression, and response to interventions. Nevertheless, many studies have not reported or disaggregated data by sex or gender. This article describes the influence of sex-linked biology (specifically sex-linked hormones) and gender on hearing and hearing interventions, including the role of sex-linked biology and gender in modifying the association between risk factors and hearing loss, and the effects of hearing loss on quality of life and functioning. Most prevalence studies indicate that hearing loss begins earlier and is more common and severe among men than women. Intrinsic sex-linked biological differences in the auditory system may account, in part, for the predominance of hearing loss in males. Sex- and gender-related differences in the effects of noise exposure or cardiovascular disease on the auditory system may help explain some of these differences in the prevalence of hearing loss. Further still, differences in hearing aid use and uptake, and the effects of hearing loss on health may also vary by sex and gender. Recognizing that sex-linked biology and gender are key determinants of hearing health, the present review concludes by emphasizing the importance of a well-developed research platform that proactively measures and assesses sex- and gender-related differences in hearing, including in understudied populations. Such research focus is necessary to advance the field of hearing science and benefit all members of society.

Objective and Subjective Hearing Difficulties Are Associated With Lower Inhibitory Control

OBJECTIVE

Evidence suggests that hearing loss increases the risk of cognitive impairment. However, the relationship between hearing loss and cognition can vary considerably across studies, which may be partially explained by demographic and health factors that are not systematically accounted for in statistical models.

DESIGN

Middle-aged to older adult participants (N = 149) completed a web-based assessment that included speech-in-noise (SiN) and self-report measures of hearing, as well as auditory and visual cognitive interference (Stroop) tasks. Correlations between hearing and cognitive interference measures were performed with and without controlling for age, sex, education, depression, anxiety, and self-rated health.

RESULTS

The risk of having objective SiN difficulties differed between males and females. All demographic and health variables, except education, influenced the likelihood of reporting hearing difficulties. Small but significant relationships between objective and reported hearing difficulties and the measures of cognitive interference were observed when analyses were controlled for demographic and health factors. Furthermore, when stratifying analyses for males and females, different relationships between hearing and cognitive interference measures were found. Self-reported difficulty with spatial hearing and objective SiN performance were better predictors of inhibitory control in females, whereas self-reported difficulty with speech was a better predictor of inhibitory control in males. This suggests that inhibitory control is associated with different listening abilities in males and females.

CONCLUSIONS

The results highlight the importance of controlling for participant characteristics when assessing the relationship between hearing and cognitive interference, which may also be the case for other cognitive functions, but this requires further investigations. Furthermore, this study is the first to show that the relationship between hearing and cognitive interference can be captured using web-based tasks that are simple to implement and administer at home without any assistance, paving the way for future online screening tests assessing the effects of hearing loss on cognition.

Speech-in-noise testing: Innovative applications for pediatric patients, underrepresented populations, fitness for duty, clinical trials, and remote services

Speech perception testing, defined as providing standardized speech stimuli and requiring a listener to provide a behavioral and scored response, has been an integral part of the audiologic test battery since the beginning of the audiology profession. Over the past several decades, limitations in the diagnostic and prognostic validity of standard speech perception testing as routinely administered in the clinic have been noted, and the promotion of speech-in-noise testing has been highlighted. This review will summarize emerging and innovative approaches to speech-in-noise testing with a focus on five applications: (1) pediatric considerations promoting the measurement of sensory and cognitive components separately; (2) appropriately serving underrepresented populations with special attention to racial, ethnic, and linguistic minorities, as well as considering biological sex and/or gender differences as variables of interest; (3) binaural fitness for duty assessments of functional hearing for occupational settings that demand the ability to detect, recognize, and localize sounds; (4) utilization of speech-in-noise tests in pharmacotherapeutic clinical trials with considerations to the drug mechanistic action, the patient populations, and the study design; and (5) online and mobile applications of hearing assessment that increase accessibility and the direct-to-consumer market.

Athleticism and sex impact neural processing of sound

Biology and experience both influence the auditory brain. Sex is one biological factor with pervasive effects on auditory processing. Females process sounds faster and more robustly than males. These differences are linked to hormone differences between the sexes. Athleticism is an experiential factor known to reduce ongoing neural noise, but whether it influences how sounds are processed by the brain is unknown. Furthermore, it is unknown whether sports participation influences auditory processing differently in males and females, given the well-documented sex differences in auditory processing seen in the general population. We hypothesized that athleticism enhances auditory processing and that these enhancements are greater in females. To test these hypotheses, we measured auditory processing in collegiate Division I male and female student-athletes and their non-athlete peers (total n = 1012) using the frequency-following response (FFR). The FFR is a neurophysiological response to sound that reflects the processing of discrete sound features. We measured across-trial consistency of the response in addition to fundamental frequency (F0) and harmonic encoding. We found that athletes had enhanced encoding of the harmonics, which was greatest in the female athletes, and that athletes had more consistent responses than non-athletes. In contrast, F0 encoding was reduced in athletes. The harmonic-encoding advantage in female athletes aligns with previous work linking harmonic encoding strength to female hormone levels and studies showing estrogen as mediating athlete sex differences in other sensory domains. Lastly, persistent deficits in auditory processing from previous concussive and repetitive subconcussive head trauma may underlie the reduced F0 encoding in athletes, as poor F0 encoding is a hallmark of concussion injury.

Difference in cochlear length between male and female patients

Objective: To compare cochlear duct length (CDL) between male and female patients by evaluating the diameter of the basal turn (distance A) on CT scans.Method: All temporal bone CT scans performed between 2014 and 2020 were reviewed in our medical center. Using multiplanar reconstructions, the length A, which is the greatest distance of the basal turn was measured on both sides. We performed an analysis of variance considering two factors: sex and side. Two different physicians carried out the measurements, an otolaryngologist and a neuroradiologist. The patients who had several CT scans allowed us to evaluate the reliability of our procedure.Results: Among the 888 CT scans reviewed, 8 were excluded because of cochlear malformations. The inter-sex difference of length A was found to be 0.29 millimeters(mm) 95% IC [0.26-0.34] and was longer in the male group (p < 0.0001). Using Alexiades' equation, we found that CDL was 34.5mm [34.37-34.61] in the male group and 33.3mm [33.13-33.38] in the female group. When one side was compared to the other, there was no significant difference (p = 0.226). An intra-class correlation found a good absolute agreement between the two screeners of 0.79.Conclusion: Males have a statistically significant longer CDL than females.

The audiogram: Detection of pure-tone stimuli in ototoxicity monitoring and assessments of investigational medicines for the inner ear

Pure-tone thresholds have long served as a gold standard for evaluating hearing sensitivity and documenting hearing changes related to medical treatments, toxic or otherwise hazardous exposures, ear disease, genetic disorders involving the ear, and deficits that develop during aging. Although the use of pure-tone audiometry is basic and standard, interpretation of thresholds obtained at multiple frequencies in both ears over multiple visits can be complex. Significant additional complexity is introduced when audiometric tests are performed within ototoxicity monitoring programs to determine if hearing loss occurs as an adverse reaction to an investigational medication and during the design and conduct of clinical trials for new otoprotective agents for noise and drug-induced hearing loss. Clinical trials using gene therapy or stem cell therapy approaches are emerging as well with audiometric outcome selection further complicated by safety issues associated with biological therapies. This review addresses factors that must be considered, including test-retest variability, significant threshold change definitions, use of ototoxicity grading scales, interpretation of early warning signals, measurement of notching in noise-induced hearing loss, and application of age-based normative data to interpretation of pure-tone thresholds. Specific guidance for clinical trial protocols that will assure rigorous methodological approaches and interpretable audiometric data are provided.

Hearing Loss and Cognition: What We Know and Where We Need to Go

Although a causal association remains to be determined, epidemiologic evidence suggests an association between hearing loss and increased risk of dementia. If we determine the association is causal, opportunity for targeted intervention for hearing loss may play a fundamental role in dementia prevention. In this discussion, we summarize current research on the association between hearing loss and dementia and review potential casual mechanisms behind the association (e.g., sensory-deprivation hypothesis, information-degradation hypothesis, common cause). We emphasize key areas of research which might best inform our investigation of this potential casual association. These selected research priorities include examination of the causal mechanism, measurement of co-existing hearing loss and cognitive impairment and determination of any bias in testing, potential for managing hearing loss for prevention of dementia and cognitive decline, or the potential to reduce dementia-related symptoms through the management of hearing loss. Addressing these research gaps and how results are then translated for clinical use may prove paramount for dementia prevention, management, and overall health of older adults.

Association Between Sensorineural Hearing Loss and Vitiligo: A Nationwide Population-Based Cohort Study

BACKGROUND

Vitiligo is an acquired depigmentation disease of the skin due to melanocyte destruction. A shared pathogenesis affecting melanocytes in the cochlea has been postulated. However, the association between vitiligo and sensorineural hearing loss (SNHL) is unclear.

OBJECTIVE

To identify the association between vitiligo and SNHL.

METHODS

This retrospective, nationwide cohort study included patients with vitiligo and age-, sex-, and comorbidities-matched controls (propensity score matching; 1:4 ratio) from the National Health Insurance Research Database in Taiwan from January 1, 2000 to December 31, 2013.

RESULTS

In total, 13048 patients with vitiligo and 52192 controls were included. SNHL developed in 0.61% patients with vitiligo and 0.29% controls. After adjusting for sex, age, and comorbidities, a significant association between vitiligo and SNHL was found (adjusted hazard ratio, 2.18; 95% CI, 1.66-2.86). The other risk factors for developing SNHL included increased age, male sex, hyperlipidemia, coronary artery disease, and diffuse connective tissue diseases. In subgroup analysis, the association between vitiligo and SNHL remained significant in almost all the subgroups.

CONCLUSION

A 2.2-fold increased risk of developing SNHL was found in patients with vitiligo. Proper referral to otologists for early screening and closer follow-up of SNHL should be considered for patients with vitiligo, especially for patients with older age.

Hearing loss and hypertension among noise-exposed workers: a pilot study based on baseline data

This study aimed to assess the prevalence of noise-induced hearing loss (NIHL) and hypertension, and the association between NIHL and hypertension using occupational physical examination data of 42,588 noise-exposed workers from local enterprises in Yangzhou between 2015 and 2017. The average binaural high-frequency threshold on average (BHFTA), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were 23.09 ± 11.32 dB, 126.85 ± 15.94 mm Hg and 79.94 ± 11.61 mm Hg. The prevalence of NIHL and hypertension were 24.38% and 25.40%. An increased risk of NIHL and hypertension was observed in the groups of males, aged >35 years, noise exposure time >5 years, noise exposure level >85 dB(A) and smoking. 32.25% NIHL workers had hypertension. NIHL workers were at higher risk of hypertension (adjusted OR = 1.07, 95%CI = 1.02-1.13). This study shows that the noise-exposed workers have high risk of developing NIHL and hypertension.

The Relevance of Leisure Noise to Hearing Threshold Shifts: A Longitudinal Analysis Among Adolescents

PURPOSE

The aim of this study was to analyze the association of total leisure noise exposure and hearing threshold shifts over 5 years among adolescents enrolled in the Ohrkan cohort study.

METHOD

The Ohrkan cohort of 2,148 students aged 13-19 years was recruited from 2009 to 2011 and followed up 5 years later. Complete baseline and follow-up reports on exposure and outcome were available for 989 participants. Leisure noise exposure was assessed by questionnaires, and clinical audiometric examinations were performed. Two outcomes were defined: occurrence of the Niskar notch pattern and audiometry showing maximum hearing threshold values at 3, 4, and 6 kHz (both ears). Longitudinal analysis using generalized estimating equations was performed.

RESULTS

High total leisure noise exposure, defined as an energy equivalent of a 40-hr week of > 85 dBA, was estimated for 32.7% of students at baseline and 63.8% at follow-up. A noise notch was observed in 1.1% of adolescents at baseline and 3.3% at follow-up. At baseline, the maximum measured threshold shift was 55 dB, which increased to 85 dB at the follow-up. Longitudinal analysis did not reveal an association between leisure noise exposure and hearing thresholds. Hearing threshold shifts or noise notches were associated with sex, school type, and time point of measurement.

CONCLUSIONS

No relationship was found between leisure noise and hearing thresholds. Male adolescents and those attending secondary general schools, with graduation following completion of ninth or 10th grade, had a greater likelihood of developing hearing threshold shifts. Prevention programs should focus on these risk groups.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19233462.

The effect of female hormone in otosclerosis. A comparative study and speculation about their effect on the ossicular chain based on the clinical results

Purpose

This study aimed at identifying gender differences in the hearing thresholds in a sample of patients with otosclerosis before and after surgery to understand the impact of female hormones on auditory thresholds.

Methods

This retrospective study analyzed 184 patients (123 women and 61 men) affected by otosclerosis. All the patients were affected by conductive hearing loss and treated by stapedoplasty. Auditory thresholds at the baseline (T0) and one month after surgery (T30) were collected. Air and bone thresholds and Air Bone Gap (ABG) were compared between females and males using one-way ANOVA.

Results

Statistically significant differences were observed comparing the air threshold at T0 vs T30 both in women and men (p < 0.0001). No statistically significant differences were observed in the bone conduction thresholds before and after surgery. The comparison between females and males showed statistically significant differences both at T0 (p < 0.01) and T30 (p < 0.05) for air conduction thresholds and ABG at 4000 Hz.

Conclusion

Although stapedoplasty reduced the difference between females and males in the air conduction thresholds and ABG, women showed better recovery of their middle ear function with better auditory thresholds and ABG. The female hormones might positively impact the ligaments of the incudostapedial joint improving chain flexibility. This benefit might explain the statistically significant difference observed in women at 4000 Hz before and after surgery.

Co-occurring Hearing Loss and Cognitive Decline in Older Adults: A Dual Group-Based Trajectory Modeling Approach

Hearing loss and cognitive impairments are both highly prevalent neurological complications for older adults. While there is growing evidence to suggest that these two conditions are interrelated, little research has been conducted that directly examines the progression and developmental trajectories of these complications contemporaneously. The aim of the study is to identify the distinct trajectory profiles for hearing loss and cognitive function in an older population over a 10-year period. Through dual trajectory modeling, the interrelationship, co-occurring movements, and overlaps between these two complications were examined. We also investigated the influence of hearing aid ownership on cognitive function trajectories. We utilized longitudinal data from 1,445 participants in the Blue Mountains Hearing Study (aged 55+ years) involving repeated measures from a population-based survey with audiometric hearing assessments. Cognitive function was assessed using the Mini-Mental State Examination (MMSE). The group-based trajectory modeling (GBTM) identified three trajectory profiles for both hearing loss and cognitive function in two older age groups (55-69 years and 70+ years). The outputs from the dual trajectories models showed the conditional probability for "no hearing loss" trajectories to be around 90% more likely to have "high-normal" cognitive function, demonstrating co-occurring overlap. In contrast, for "moderate to severe hearing loss" trajectories, the conditional probability drops to 65% and 79% for the 55-69 age group and 70+ age group respectively. There was also an increasing probability for "cognitive decline" conditional on the severity of hearing loss with 6.7%, 7.5%, and 8.7% for no hearing loss, mild hearing loss, and moderate to severe hearing loss trajectory groups. While we did not find any statistically significant difference in the influence of hearing aid use in the cognitive function trajectories, there was a consistent greater representation of non-hearing aid users in the trajectories with poorer cognitive function. This study found GBTM to identify trajectories that were in agreement with our current understanding of hearing loss and cognitive impairment in older adults. This study also adds to the existing evidence-base as dual trajectories demonstrated co-occurrence in developmental changes in these two common neurological complications for the older population.

Relationship Between Peripheral and Central Auditory Abilities and Iron Deficiency Anemia in Adolescent Girls

PURPOSE

This study evaluated the peripheral hearing and central auditory processing abilities in Indian adolescent girls with iron deficiency anemia (IDA).

METHOD

The participants consisted of 75 adolescent girls with IDA, 50 adolescent girls without IDA, and 50 adolescent boys without IDA. Participants underwent a test battery to evaluate auditory processing and peripheral hearing assessment. In this study, central auditory processing abilities were assessed using Speech Perception in Noise test in Kannada (SPIN-K) and quick speech perception in noise tests in Kannada, dichotic consonant-vowel test, gap detection threshold (GDT), and auditory digit sequencing and auditory digit span tests.

RESULTS

Results showed that the hearing thresholds at extremely low and high frequencies (250 and 8000 Hz), although within clinically normal limits, were poorer in girls with IDA than in the control groups. Also, girls with IDA performed poorly in SPIN-K of the right ear, GDT, and auditory backward digit span tests.

CONCLUSION

These subtle auditory deficiencies may be attributed to the compromised blood supply to the central auditory nervous system, as observed in the current study.

Estradiol Protects against Noise-Induced Hearing Loss and Modulates Auditory Physiology in Female Mice

Recent studies have identified sex-differences in auditory physiology and in the susceptibility to noise-induced hearing loss (NIHL). We hypothesize that 17β-estradiol (E2), a known modulator of auditory physiology, may underpin sex-differences in the response to noise trauma. Here, we gonadectomized B6CBAF1/J mice and used a combination of electrophysiological and histological techniques to study the effects of estrogen replacement on peripheral auditory physiology in the absence of noise exposure and on protection from NIHL. Functional analysis of auditory physiology in gonadectomized female mice revealed that E2-treatment modulated the peripheral response to sound in the absence of changes to the endocochlear potential compared to vehicle-treatment. E2-replacement in gonadectomized female mice protected against hearing loss following permanent threshold shift (PTS)- and temporary threshold shift (TTS)-inducing noise exposures. Histological analysis of the cochlear tissue revealed that E2-replacement mitigated outer hair cell loss and cochlear synaptopathy following noise exposure compared to vehicle-treatment. Lastly, using fluorescent in situ hybridization, we demonstrate co-localization of estrogen receptor-2 with type-1C, high threshold spiral ganglion neurons, suggesting that the observed protection from cochlear synaptopathy may occur through E2-mediated preservation of these neurons. Taken together, these data indicate the estrogen signaling pathways may be harnessed for the prevention and treatment of NIHL.

Auditory sensory deprivation induced by noise exposure exacerbates cognitive decline in a mouse model of Alzheimer's disease

Although association between hearing impairment and dementia has been widely documented by epidemiological studies, the role of auditory sensory deprivation in cognitive decline remains to be fully understood. To address this issue we investigated the impact of hearing loss on the onset and time-course of cognitive decline in an animal model of Alzheimer's disease (AD), that is the 3×Tg-AD mice and the underlying mechanisms. We found that hearing loss induced by noise exposure in the 3×Tg-AD mice before the phenotype is manifested caused persistent synaptic and morphological alterations in the auditory cortex. This was associated with earlier hippocampal dysfunction, increased tau phosphorylation, neuroinflammation, and redox imbalance, along with anticipated memory deficits compared to the expected time-course of the neurodegenerative phenotype. Our data suggest that a mouse model of AD is more vulnerable to central damage induced by hearing loss and shows reduced ability to counteract noise-induced detrimental effects, which accelerates the neurodegenerative disease onset.

Patterns of Prevalence of Multiple Sensory Impairments among Community-Dwelling Older Adults

BACKGROUND

Much is known about individual sensory deficits among older adults, but there is a dearth of information about the prevalence of multiple concurrent sensory deficits in this population.

METHODS

We evaluated the prevalence of individual and multiple sensory impairments at the most recent clinic visit among participants aged 24 years and older in the Baltimore Longitudinal Study of Aging (BLSA) (hearing, vision, olfaction, proprioception, and vestibular function) and Atherosclerosis Risk in Communities Study (ARIC) (hearing, vision, olfaction). We compared observed prevalence of multiple sensory impairments with expected prevalence based on compounded probabilities of multiple impairments using Fisher Exact Tests. Also, we evaluated the comparability of different measures used between these two studies.

RESULTS

In both studies, the prevalence of each individual sensory impairment was common (>10%), and higher with older age, and the most common pattern of co-occurring sensory impairments was hearing and visual impairments (17.4% [BLSA]; 50.2% [ARIC]). In BLSA, the pattern that differed the most between observed and expected prevalence was combined hearing, vision, and olfactory impairments (observed 5.2% vs. 1.4% expected, p=0.01). In ARIC, this difference was much smaller (observed 8.1% vs. 7.2% expected, p=0.49).

CONCLUSIONS

Although concurrent hearing and vision impairments were the most common co-occurring deficits, combined hearing, vision and olfactory impairments are most likely to co-occur above chance, especially at older ages.

Temporal Alterations to Central Auditory Processing without Synaptopathy after Lifetime Exposure to Environmental Noise

People are increasingly exposed to environmental noise through the cumulation of occupational and recreational activities, which is considered harmless to the auditory system, if the sound intensity remains <80 dB. However, recent evidence of noise-induced peripheral synaptic damage and central reorganizations in the auditory cortex, despite normal audiometry results, has cast doubt on the innocuousness of lifetime exposure to environmental noise. We addressed this issue by exposing adult rats to realistic and nontraumatic environmental noise, within the daily permissible noise exposure limit for humans (80 dB sound pressure level, 8 h/day) for between 3 and 18 months. We found that temporary hearing loss could be detected after 6 months of daily exposure, without leading to permanent hearing loss or to missing synaptic ribbons in cochlear hair cells. The degraded temporal representation of sounds in the auditory cortex after 18 months of exposure was very different from the effects observed after only 3 months of exposure, suggesting that modifications to the neural code continue throughout a lifetime of exposure to noise.

Envelope following response measurements in young veterans are consistent with noise-induced cochlear synaptopathy

Animal studies have demonstrated that noise exposure can lead to the loss of the synapses between the inner hair cells and their afferent auditory nerve fiber targets without impacting auditory thresholds. Although several non-invasive physiological measures appear to be sensitive to cochlear synaptopathy in animal models, including auditory brainstem response (ABR) wave I amplitude, the envelope following response (EFR), and the middle ear muscle reflex (MEMR), human studies of these measures in samples that are expected to vary in terms of the degree of noise-induced synaptopathy have resulted in mixed findings. One possible explanation for the differing results is that synaptopathy risk is lower for recreational noise exposure than for occupational or military noise exposure. The goal of this analysis was to determine if EFR magnitude and ABR wave I amplitude are reduced among young Veterans with a history of military noise exposure compared with non-Veteran controls with minimal noise exposure. EFRs and ABRs were obtained in a sample of young (19-35 years) Veterans and non-Veterans with normal audiograms and robust distortion product otoacoustic emissions (DPOAEs). The statistical analysis is consistent with a reduction in mean EFR magnitude and ABR wave I amplitude (at 90 dB peSPL) for Veterans with a significant history of noise exposure compared with non-Veteran controls. These findings are in agreement with previous ABR wave I amplitude findings in young Veterans and are consistent with animal models of noise-induced cochlear synaptopathy.

Sex Differences in Otolaryngology: Focus on the Emerging Role of Estrogens in Inflammatory and Pro-Resolving Responses

Otolaryngology (also known as ear, nose, and throat (ENT)) diseases can be significantly affected by the level of sex hormones, which indicates that sex differences affect the manifestation, pathophysiology, and outcomes of these diseases. Recently, increasing evidence has suggested that proinflammatory responses in ENT diseases are linked to the level of sex hormones. The sex hormone receptors are present on a wide variety of immune cells; therefore, it is evident that they play crucial roles in regulating the immune system and hence affect the disease progression of ENT diseases. In this review, we focus on how sex hormones, particularly estrogens, regulate ENT diseases, such as chronic rhinosinusitis, vocal fold polyps, thyroid cancer, Sjögren’s syndrome, and head and neck cancers, from the perspectives of inflammatory responses and specialized proresolving mediator-driven resolution. This paper aims to clarify why considering sex differences in the field of basic and medical research on otolaryngology is a key component to successful therapy for both males and females in the future.

Sex Differences in the Triad of Acquired Sensorineural Hearing Loss

The triad of noise-generated, drug-induced, and age-related hearing loss is the major cause of acquired sensorineural hearing loss (ASNHL) in modern society. Although these three forms of hearing loss display similar underlying mechanisms, detailed studies have revealed the presence of sex differences in the auditory system both in human and animal models of ASNHL. However, the sexual dimorphism of hearing varies among noise-induced hearing loss (NIHL), ototoxicity, and age-related hearing loss (ARHL). Importantly, estrogen may play an essential role in modulating the pathophysiological mechanisms in the cochlea and several reports have shown that the effects of hormone replacement therapy on hearing loss are complex. This review will summarize the clinical features of sex differences in ASNHL, compare the animal investigations of cochlear sexual dimorphism in response to the three insults, and address how estrogen affects the auditory organ at molecular levels.

Clinical and genetic risk factors for radiation-associated ototoxicity: A report from the Childhood Cancer Survivor Study and the St. Jude Lifetime Cohort

BACKGROUND

Cranial radiation therapy (CRT) is associated with ototoxicity, which manifests as hearing loss and tinnitus. The authors sought to identify clinical determinants and genetic risk factors for ototoxicity among adult survivors of pediatric cancer treated with CRT.

METHODS

Logistic regression evaluated associations of tinnitus (n = 1991) and hearing loss (n = 2198) with nongenetic risk factors and comorbidities among CRT-treated survivors in the Childhood Cancer Survivor Study. Genome-wide association studies (GWASs) of CRT-related tinnitus and hearing loss were also performed.

RESULTS

Males were more likely to report CRT-related tinnitus (9.4% vs 5.4%; P = 5.1 × 10^-4 ) and hearing loss (14.0% vs 10.7%; P = .02) than females. Survivors with tinnitus or hearing loss were more likely to experience persistent dizziness or vertigo (tinnitus: P < 2 × 10^-16 ; hearing loss: P = 6.4 × 10^-9 ), take antidepressants (tinnitus: P = .02; hearing loss: P = .01), and report poorer overall health (tinnitus: P = 1.5 × 10^-6 ; hearing loss: P = 1.7 × 10^-6 ) in comparison with controls. GWAS of CRT-related tinnitus revealed a genome-wide significant signal in chromosome 1 led by rs203248 (P = 1.5 × 10^-9 ), whereas GWAS of CRT-related hearing loss identified rs332013 (P = 5.8 × 10^-7 ) in chromosome 8 and rs67522722 (P = 7.8 × 10^-7 ) in chromosome 6 as nearly genome-wide significant. A replication analysis identified rs67522722, intronic to ATXN1, as being significantly associated with CRT-related hearing loss (P = .03) and de novo hearing loss (P = 3.6 × 10^-4 ).

CONCLUSIONS

CRT-associated ototoxicity was associated with sex, several neuro-otological symptoms, increased antidepressant use, and poorer self-reported health. GWAS of CRT-related hearing loss identified rs67522722, which was supported in an independent cohort of survivors.

LAY SUMMARY

Hearing loss and subjective tinnitus (the perception of noise or ringing in the ear) are long-term side effects of cancer treatment and are common in children treated with radiation to the brain. These toxicities can affect childhood development and potentially contribute to serious learning and behavioral difficulties. This study's data indicate that males are at greater risk for hearing loss and tinnitus than females after radiation therapy to the brain. Those who develop these toxicities are more likely to use antidepressants and report poorer overall health. Health care providers can improve the management of survivors by informing patients and/or their parents of these risks.

Racial/Ethnic and Sex Representation in US-Based Clinical Trials of Hearing Loss Management in Adults: A Systematic Review

Importance

Although the National Institutes of Health (NIH) mandated the inclusion and reporting of women and racial or ethnic minority groups in NIH-funded research in 1993, little is known regarding the representation of women and racial or ethnic minority groups in trials that investigate hearing loss management.

Objective

To assess sex and racial/ethnic representation in US-based clinical trials of hearing loss management in an adult population.

Data Sources

Pertinent studies were identified using search strategies in PubMed, Embase, and ClinicalTrials.gov.

Study Selection

Our search strategy yielded 6196 studies. We included prospective studies that were written in English, performed in the US, and evaluated hearing loss management in adults, including amplification devices, such as hearing aids or assistive listening devices, cochlear implants, aural rehabilitation, and therapeutics. Given its prevalence, only studies that addressed bilateral sensorineural hearing loss were included.

Data Extraction and Synthesis

Data from 125 studies were extracted. The Preferred Reporting Items for Systematic Reviews and Meta-analyses diagram for systematic reviews was used for abstracting data. The guidelines were applied using independent extraction by multiple observers.

Results

Among 125 clinical studies performed from January 1990 to July 2020 regarding hearing loss management, only 16 (12.8%) reported race/ethnicity, and 88 (70.4%) reported sex. Of the 16 studies that reported race/ethnicity, only 5 included more than 30% non-White representation. Among the 88 articles that reported sex, 44 (35.2%) reported more than 45% female representation. While the mean number of participants included in the observed trials was 80 (range, 7-644), the median number of participants from racial or ethnic minority groups in studies that reported race/ethnicity was 9 (range, 1-77), and a median of 12 female participants were included in studies with a numerical breakdown by sex. A mean of 41% (range, 1.55%-77.5%) of participants were female among studies that reported sex, and a mean of 30% (range, 1.96%-100%) of participants were from racial or ethnic minority groups among the 16 studies that reported race/ethnicity. Reporting of race/ethnicity varied substantially by funding source and journal type, while reporting by sex differed only by journal type.

Conclusions and Relevance

Studies investigating hearing loss management do not adequately reflect the US population. A closer examination of the inclusion of diverse adults in clinical research associated with hearing health may work to ameliorate disparities and contribute to the development of tailored interventions that address the needs of an increasingly diverse US population.

Sex differences in biological aging with a focus on human studies

Aging is a complex biological process characterized by hallmark features accumulating over the life course, shaping the individual's aging trajectory and subsequent disease risks. There is substantial individual variability in the aging process between men and women. In general, women live longer than men, consistent with lower biological ages as assessed by molecular biomarkers, but there is a paradox. Women are frailer and have worse health at the end of life, while men still perform better in physical function examinations. Moreover, many age-related diseases show sex-specific patterns. In this review, we aim to summarize the current knowledge on sexual dimorphism in human studies, with support from animal research, on biological aging and illnesses. We also attempt to place it in the context of the theories of aging, as well as discuss the explanations for the sex differences, for example, the sex-chromosome linked mechanisms and hormonally driven differences.