A polymorphism in human Estrogen-related receptor beta (ESRRß) is associated with physiological measures of noise-induced hearing loss

Noise-induced hearing loss (NIHL) is a common form of hearing loss and a growing health concern despite national standards for hearing protection and public health awareness campaigns. An NIHL gene association study with college-aged musicians has associated a non-synonymous single nucleotide polymorphism (rs61742642; C?T, P386S) in the ligand-binding domain of human estrogen-related receptor beta (ESRRß) with increased susceptibility to bilateral 4 to 6 kHz hearing loss. ESRRß protein is expressed in major cochlear structures except hair cells and tectorial membrane. ESRRß controls epithelial cell fate and endolymph production in the stria vascularis by regulating genes responsible for potassium ion transportation. Mutation in ESRRß gene is associated with autosomal-recessive nonsyndromic profound hearing loss. The purpose of the study was to examine the effects of the ESRRß polymorphism increased susceptibility to NIHL, and also indicates the efficacy of otoacoustic emissions testing for identifying sound processing endophenotypes. on temporary NIHL in young individuals. Methods: 19 individuals with rs61742642 CT genotype and 40 individuals with rs61742642 CC genotype were recruited for the study. Temporary NIHL was induced by 10 minutes exposure to 90 dB SL 2 kHz audiometric narrow-band noise and cochlear physiology was evaluated by a battery of clinical tests consisting audiometry, distortion product of otoacoustic emission (DPOAE) and transient evoked otoacoustic emissions (TEOAE). Input-output function of distortion product of OAE (DPOAE) was collected before and after the noise exposure using L1 = (0.40) L2 +39 at 2, 3 and 4 kHz. TEOAEs were collected using ILO quickscreen protocol with 84 dB peSLP with and without 50 dB SL contralateral broadband noise. Audiometric temporary threshold shift (ATTS),DPOAE temporary level shift (DPTLS), TEOAE temporary level shift (TETLS), TEOAE temporary level shift (TETLS) and TEOAE temporary suppression shift (TETSS) were evaluated to explore physiological basis of NIHL susceptibility related with the ESRRß polymorphism. Results: A multiple regression analysis showed that individuals with rs61742642 CT genotype showed greater ATTS (ß= 10.498 dB, CI = 6.413 – 14.583, p <0.001) without convincing evidence of change in DPTLS (ß = -0.037 dB, CI = -0.663 – 0.589, p= 0.906), TETLS (ß = -0.467 dB, CI = -1.573 – 0.640, p = 0.401) and TETSS (ß = 0.224 dB, CI = -0.111 – 0.559, p = 0.186) compared with individuals with rs61742642 CC genotype. Individuals with the CT genotype showed poorer pre-exposure audiometric thresholds from 3 to 6 kHz in both ears with compromised DPOAE amplitude (ß = -1.409 dB, CI = -2.662 – -0.156, p = 0.028) and TEOAE signal-to-noise ratio (F(1, 53) = 5.23, p= 0.026) in left ear. TEOAE 1/3 octave signal-to-noise ratios were higher (F(1, 53) =5.037, p = 0.029) for females compared to males. Conclusion: The results indicate that individuals with the CT genotype are likely to get greater amount of metabolic compromise in cochlear physiology compared with individuals carrying CC genotype. The study associated the rs61742642 CT genotype with compromised pre-exposure poorer audiometric thresholds, reduced DPOAE amplitude and compromised TEOAE signal-to-noise ratio compared to individuals with CC genotype. The study suggests that the ESRRß polymorphism is associated with increased susceptibility to NIHL, and also indicates the efficacy of otoacoustic emissions testing for identifying sound processing endophenotypes

Auditory Electrophysiological and Perceptual Measures in Student Musicians with High Sound Exposure

This study aimed to determine (a) the influence of noise exposure background (NEB) on the peripheral and central auditory system functioning and (b) the influence of NEB on speech recognition in noise abilities in student musicians. Twenty non-musician students with self-reported low NEB and 18 student musicians with self-reported high NEB completed a battery of tests that consisted of physiological measures, including auditory brainstem responses (ABRs) at three different stimulus rates (11.3 Hz, 51.3 Hz, and 81.3 Hz), and P300, and behavioral measures including conventional and extended high-frequency audiometry, consonant–vowel nucleus–consonant (CNC) word test and AzBio sentence test for assessing speech perception in noise abilities at −9, −6, −3, 0, and +3 dB signal to noise ratios (SNRs). The NEB was negatively associated with performance on the CNC test at all five SNRs. A negative association was found between NEB and performance on the AzBio test at 0 dB SNR. No effect of NEB was found on the amplitude and latency of P300 and the ABR wave I amplitude. More investigations of larger datasets with different NEB and longitudinal measurements are needed to investigate the influence of NEB on word recognition in noise and to understand the specific cognitive processes contributing to the impact of NEB on word recognition in noise

Identifying Health-Related Conditions Associated with Tinnitus in Young Adults

Objective: The present study investigated the epidemic of tinnitus in college-aged young adults. Our first objective was to identify health conditions associated with tinnitus in young adults. The second objective was to evaluate the predictive utility of some known risk factors. Study design: A cross-sectional design was used to investigate the prevalence and risk factors for tinnitus. Setting: A questionnaire was distributed, reaching out to a large college-aged population. A total of 2258 young adults aged 18–30 years were recruited from April 2021 to February 2022. Interventions: A questionnaire was administered to investigate the epidemiology of tinnitus in a population of college-aged young adults. Results: About 17.7% of young adults reported bothersome tinnitus perception lasting for ≥5 min in the last 12 months. The prevalence of chronic tinnitus (bothersome tinnitus for ≥1 year) and acute tinnitus (bothersome tinnitus for <1 year) was 10.6% and 7.1%, respectively. About 19% of the study sample reported at least one health condition. Individuals reporting head injury, hypertension, heart disease, scarlet fever, and malaria showed significantly higher odds of reporting chronic tinnitus. Meningitis and self-reported hearing loss showed significant associations with bothersome tinnitus. The prevalence of chronic tinnitus was significantly higher in males reporting high noise exposure, a positive history of reoccurring ear infections, European ethnic background, and a positive health history. Risk modeling showed that noise exposure was the most important risk factor for chronic tinnitus, followed by sex, reoccurring ear infections, and a history of any health condition. A positive history of COVID-19 and self-reported severity showed no association with tinnitus. Individuals reporting reoccurring ear infections showed a significantly higher prevalence of COVID-19. Conclusions: While young adults with health conditions are at a higher risk of reporting tinnitus, the predictive utility of a positive health history remains relatively low, possibly due to weak associations between health conditions and tinnitus. Noise, male sex, reoccurring ear infections, European ethnicity, and a positive health history revealed higher odds of reporting chronic tinnitus than their counterparts. These risk factors collectively explained about 16% variability in chronic tinnitus, which highlights the need for identifying other risk factors for chronic tinnitus in young adults