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Hearing Research Dec 2014C57BL/6 inbred mice are frequently used as models in auditory research, mostly the C57BL/6J and C57BL/6N substrains. Genetic variation and phenotypic disparities between... (Comparative Study)
Comparative Study
C57BL/6 inbred mice are frequently used as models in auditory research, mostly the C57BL/6J and C57BL/6N substrains. Genetic variation and phenotypic disparities between these two substrains have been extensively investigated, but conflicting information exists about differences in their auditory and vestibular phenotypes. Literature-based comparisons are rendered difficult or impossible because most auditory publications do not designate the substrain used. We therefore evaluated commercial C57BL/6N and C57BL/6J mice for their baseline auditory brainstem response (ABR) thresholds at 3 months of age as well as their susceptibility to noise exposure and aminoglycoside antibiotics. Both substrains have similar thresholds at 4 and 12 kHz, but C57BL/6N show significantly higher baseline thresholds at 24 and 32 kHz. Because of these elevated thresholds, the N substrain is unsuitable as a model for drug ototoxicity, which primarily affects high frequencies. Exposure to 2-20 kHz broadband noise for 2 h at 110 dB produced significantly higher threshold shifts in the J substrain. These results suggest caution in the selection of C57BL/6 substrains for auditory research and indicate the need to specify substrains, age and the breeding source in all publications.
Topics: Animals; Anti-Bacterial Agents; Auditory Pathways; Auditory Threshold; Kanamycin; Male; Mice; Mice, Inbred C57BL; Noise; Phenotype; Vestibule, Labyrinth
PubMed: 25456090
DOI: 10.1016/j.heares.2014.10.005 -
Scientific Reports Nov 2023Tinnitus, reduced sound-level tolerance, and difficulties hearing in noisy environments are the most common complaints associated with sensorineural hearing loss in...
Tinnitus, reduced sound-level tolerance, and difficulties hearing in noisy environments are the most common complaints associated with sensorineural hearing loss in adult populations. This study aims to clarify if cochlear neural degeneration estimated in a large pool of participants with normal audiograms is associated with self-report of tinnitus using a test battery probing the different stages of the auditory processing from hair cell responses to the auditory reflexes of the brainstem. Self-report of chronic tinnitus was significantly associated with (1) reduced cochlear nerve responses, (2) weaker middle-ear muscle reflexes, (3) stronger medial olivocochlear efferent reflexes and (4) hyperactivity in the central auditory pathways. These results support the model of tinnitus generation whereby decreased neural activity from a damaged cochlea can elicit hyperactivity from decreased inhibition in the central nervous system.
Topics: Adult; Humans; Tinnitus; Auditory Threshold; Hearing; Cochlea; Auditory Perception; Vestibulocochlear Nerve Diseases
PubMed: 38036538
DOI: 10.1038/s41598-023-46741-5 -
Trends in Hearing Aug 2016It is well-established that hearing loss does not only lead to a reduction of hearing sensitivity. Large individual differences are typically observed among listeners...
It is well-established that hearing loss does not only lead to a reduction of hearing sensitivity. Large individual differences are typically observed among listeners with hearing impairment in a wide range of suprathreshold auditory measures. In many cases, audiometric thresholds cannot fully account for such individual differences, which make it challenging to find adequate compensation strategies in hearing devices. How to characterize, model, and compensate for individual hearing loss were the main topics of the fifth International Symposium on Auditory and Audiological Research (ISAAR), held in Nyborg, Denmark, in August 2015. The following collection of papers results from some of the work that was presented and discussed at the symposium.
Topics: Auditory Threshold; Denmark; Hearing Loss; Hearing Loss, Sensorineural; Hearing Tests; Humans
PubMed: 27566802
DOI: 10.1177/2331216516655890 -
Otolaryngology--head and Neck Surgery :... Jul 2022Little is known about peripheral auditory function in young adults with HIV, who might be expected to show early evidence of hearing loss if HIV infection or treatment...
OBJECTIVE
Little is known about peripheral auditory function in young adults with HIV, who might be expected to show early evidence of hearing loss if HIV infection or treatment does affect peripheral function. The goal of this study was to compare peripheral auditory function in 2 age- and gender-matched groups of young adults with clinically normal hearing with and without HIV.
STUDY DESIGN
Matched cohort study with repeated measures.
SETTING
Infectious disease center in Dar es Salaam, Tanzania.
METHODS
Participants included HIV-positive (n = 38) and HIV-negative (n = 38) adults aged 20 to 30 years who had clinically normal hearing, defined as type A tympanograms, air conduction thresholds ≤25 dB HL bilaterally from 0.5 to 8 kHz, and distortion product otoacoustic emissions (DPOAEs) >6 dB above the noise floor bilaterally from 1.5 to 8 kHz. Participants were tested multiple times over 6-month intervals (average, 2.7 sessions/participant) for a total of 208 observations. Primary outcome measures included tympanograms, air conduction audiograms, DPOAEs, and click-evoked auditory brainstem responses.
RESULTS
HIV groups did not significantly differ in age, static immittance, or air conduction thresholds. HIV-positive status was independently associated with approximately 3.7-dB lower DPOAE amplitudes from 2 to 8 kHz (95% CI, 1.01-6.82) in both ears and 0.04-µV lower (95% CI, 0.003-0.076) auditory brainstem response wave I amplitudes in the right ear.
CONCLUSION
Young adults living with HIV have slightly but reliably smaller DPOAEs and auditory brainstem response wave I amplitudes than matched HIV-negative controls. The magnitude of these differences is small, but these results support measuring peripheral auditory function in HIV-positive individuals as they age.
Topics: Audiometry, Pure-Tone; Auditory Threshold; Cohort Studies; Evoked Potentials, Auditory, Brain Stem; HIV Infections; Hearing; Humans; Otoacoustic Emissions, Spontaneous; Tanzania; Young Adult
PubMed: 34546820
DOI: 10.1177/01945998211047147 -
Journal of Speech, Language, and... Feb 2019Purpose A Bayesian adaptive procedure, that is, the quick auditory filter (qAF) procedure, has been shown to improve the efficiency for estimating auditory filter shapes...
Purpose A Bayesian adaptive procedure, that is, the quick auditory filter (qAF) procedure, has been shown to improve the efficiency for estimating auditory filter shapes of listeners with normal hearing. The current study evaluates the accuracy and test-retest reliability of the qAF procedure for naïve listeners with a variety of ages and hearing status. Method Fifty listeners who were naïve to psychophysical experiments and exhibit wide ranges of age (19-70 years) and hearing threshold (-5 to 70 dB HL at 2 kHz) were recruited. Their auditory filter shapes were estimated for a 15-dB SL target tone at 2 kHz using both the qAF procedure and the traditional threshold-based procedure. The auditory filter model was defined using 3 parameters: (a) the sharpness of the tip portion of the auditory filter, p; (b) the prominence of the low-frequency tail of the filter, 10log( w); and (c) the listener's efficiency in detection, 10log( K). Results The estimated parameters of the auditory filter model were consistent between 2 qAF runs tested on 2 separate days. The parameter estimates from the 2 qAF runs also agreed well with those estimated using the traditional procedure despite being substantially faster. Across the 3 auditory filter estimates, the dependence of the auditory filter parameters on listener age and hearing threshold was consistent across procedures, as well as consistent with previously published estimates. Conclusions The qAF procedure demonstrates satisfactory test-retest reliability and good agreement to the traditional procedure for listeners with a wide range of ages and with hearing status ranging from normal hearing to moderate hearing impairment.
Topics: Adult; Aged; Auditory Perception; Auditory Threshold; Bayes Theorem; Discrimination, Psychological; Hearing; Humans; Middle Aged; Noise; Perceptual Masking; Reproducibility of Results; Young Adult
PubMed: 30950687
DOI: 10.1044/2018_JSLHR-H-18-0092 -
Hearing Research Dec 2023Aging is an inevitable phase in mammals that leads to health impairments, including hearing loss. Age-related hearing loss (AHL) leads to psychosocial problems and...
Aging is an inevitable phase in mammals that leads to health impairments, including hearing loss. Age-related hearing loss (AHL) leads to psychosocial problems and cognitive decline in the elderly. In this study, mean thresholds of auditory brainstem responses (ABR) and distortion-product otoacoustic emissions (DPOAE) increased at multiple frequencies in aged rats (14 months old) compared to young rats (2 months old). Using untargeted ultra-high performance liquid chromatography-mass spectroscopy (LC-MS), we quantified molecular metabolic markers in the cochlea of aged rats with hearing loss. A total of 137 different metabolites were identified in two groups, highlighting several prominent metabolic pathways related to purine metabolism; glycine, serine, and threonine metabolism; arginine and proline metabolism; and pyrimidine metabolism. In addition, the beneficial effects of purine supplementation were demonstrated in a mimetic model of senescent marginal cells (MCs). Overall, altered metabolic profiling is both the cause and manifestation of pathology, and our results suggest that cellular senescence and dysfunctional cochlear metabolism may contribute to the progression of AHL. These findings are seminal in elucidating the pathophysiological mechanisms underlying AHL and serve as a basis for future clinical predictions and interventions in AHL.
Topics: Humans; Aged; Rats; Animals; Infant; Otoacoustic Emissions, Spontaneous; Cochlea; Presbycusis; Aging; Evoked Potentials, Auditory, Brain Stem; Biomarkers; Purines; Auditory Threshold; Mammals
PubMed: 37939412
DOI: 10.1016/j.heares.2023.108913 -
PloS One 2021Auditory brainstem responses (ABRs) and auditory middle-latency responses (AMLRs) to a click stimulus were measured in about 100 subjects. Of interest were the sex...
Auditory brainstem responses (ABRs) and auditory middle-latency responses (AMLRs) to a click stimulus were measured in about 100 subjects. Of interest were the sex differences in those auditory evoked potentials (AEPs), the correlations between the various AEP measures, and the correlations between the AEP measures and measures of otoacoustic emissions (OAEs) and behavioral performance also measured on the same subjects. Also of interest was how the menstrual cycle affected the various AEP measures. Most ABR measures and several AMLR measures exhibited sex differences, and many of the former were substantial. The sex differences tended to be larger for latency than for amplitude of the waves, and they tended to be larger for a weak click stimulus than for a strong click. The largest sex difference was for Wave-V latency (effect size ~1.2). When subjects were dichotomized into Non-Whites and Whites, the race differences in AEPs were small within sex. However, sex and race interacted so that the sex differences often were larger for the White subjects than for the Non-White subjects, particularly for the latency measures. Contrary to the literature, no AEP measures differed markedly across the menstrual cycle. Correlations between various AEP measures, and between AEP and OAE measures, were small and showed no consistent patterns across sex or race categories. Performance on seven common psychoacoustical tasks was only weakly correlated with individual AEP measures (just as was true for the OAEs also measured on these subjects). AMLR Wave Pa unexpectedly did not show the decrease in latency and increase in amplitude typically observed for AEPs when click level was varied from 40 to 70 dB nHL (normal Hearing Level). For the majority of the measures, the variability of the distribution of scores was greater for the males than for the females.
Topics: Acoustic Stimulation; Audiometry; Auditory Perception; Auditory Threshold; Evoked Potentials, Auditory; Evoked Potentials, Auditory, Brain Stem; Female; Hearing; Hearing Tests; Humans; Male; Menstrual Cycle; Psychoacoustics; Race Factors; Reaction Time; Sex Factors; Young Adult
PubMed: 33979393
DOI: 10.1371/journal.pone.0251363 -
American Journal of Audiology Jun 2023Common clinical application of auditory brainstem response (ABR) testing is limited to 0.25-4 kHz. Prior research has demonstrated associations between ABR and...
PURPOSE
Common clinical application of auditory brainstem response (ABR) testing is limited to 0.25-4 kHz. Prior research has demonstrated associations between ABR and behavioral thresholds for tone burst stimuli > 4 kHz in adults, but there are no comparable data for children. The ability to predict behavioral thresholds > 4 kHz clinically based on the ABR would provide valuable audiologic information for individuals who are unable to provide behavioral thresholds. This study included children with hearing loss and children with normal hearing to determine the association between ABR and behavioral thresholds at 6 and 8 kHz.
METHOD
ABR and behavioral thresholds were obtained for children ages 4.7-16.7 years ( = 10.5, = 3.4) with sensorineural hearing loss ( = 24) or normal hearing sensitivity ( = 16) and for adults ages 18.4-54.4 years ( = 32.7, = 10.4) with sensorineural hearing loss ( = 13) or normal hearing sensitivity ( = 11). Thresholds obtained for 6 and 8 kHz using ABR and conventional audiometry were compared.
RESULTS
Differences between ABR and behavioral thresholds averaged 5-6 dB for both children and adults for both test frequencies, with differences of ≤ 20 dB in all instances. Linear mixed modeling for data from participants with hearing loss suggested that ABR threshold is a good predictor of behavioral threshold at 6 and 8 kHz for both children and adults. Test specificity was 100%; no participants with behavioral thresholds ≤ 20 dB HL had ABR thresholds > 25 dB nHL.
CONCLUSIONS
Initial evidence suggests that ABR testing at 6 and 8 kHz is reliable for estimating behavioral threshold in listeners with hearing loss and accurately identifies normal hearing sensitivity. The results of this study contribute to efforts to improve outcomes for vulnerable populations by reducing barriers to clinical implementation of ABR testing at > 4 kHz.
Topics: Adult; Child; Humans; Audiometry; Audiometry, Pure-Tone; Auditory Threshold; Deafness; Evoked Potentials, Auditory, Brain Stem; Hearing Loss; Hearing Loss, Sensorineural; Child, Preschool; Adolescent; Young Adult; Middle Aged
PubMed: 37040345
DOI: 10.1044/2023_AJA-22-00180 -
Journal of Otolaryngology - Head & Neck... Mar 2016The Canadian Hearing and Auditory Research Translation (CHART) group is a newly formed taskforce to develop collaborative research initiatives. Initial discussions...
The Canadian Hearing and Auditory Research Translation (CHART) group is a newly formed taskforce to develop collaborative research initiatives. Initial discussions centered on diagnostic improvements for middle ear disease, auditory neuropathy spectrum disorder, tinnitus and presbycusis. Central to these discussions was the widely held view that the standard audiogram and its interpretation is inadequate to for describing many forms of hearing problems that we now recognize. This letter is designed to create awareness and to seek feedback from hearing healthcare professionals on their experience regarding the adequacy (or otherwise) of the audiogram in its present form.
Topics: Audiometry, Pure-Tone; Auditory Threshold; Canada; Hearing Loss; Humans
PubMed: 26965445
DOI: 10.1186/s40463-016-0132-8 -
Hearing Research Oct 2022Clinical auditory physiological measures (e.g., auditory brainstem responses, ABRs, and distortion product otoacoustic emissions, DPOAEs) provide diagnostic specificity...
Clinical auditory physiological measures (e.g., auditory brainstem responses, ABRs, and distortion product otoacoustic emissions, DPOAEs) provide diagnostic specificity for differentially diagnosing overt hearing impairments, but they remain limited in their ability to detect specific sites of lesion and subtle levels of cochlear damage. Studies in animal models may hold the key to improve differential diagnosis due to the ability to induce tightly controlled and histologically verifiable subclinical cochlear pathologies. Here, we present a normative set of traditional and clinically novel physiological measures using ABRs and DPOAEs measured in a large cohort of male macaque monkeys. Given the high similarities between macaque and human auditory anatomy, physiology, and susceptibility to hearing damage, this normative data set will serve as a crucial baseline to investigate novel physiological measures to improve diagnostics. DPOAE amplitudes were robust at f = 1.22, L/L = 65/55, increased with frequency up to 10 kHz, and exhibited high test re-test reliability. DPOAE thresholds were lowest from 2-10 kHz and highest < 2 kHz. ABRs with a standard clinical electrode montage (vertex-to-mastoid, VM) produced Waves I-IV with a less frequently observed Wave-I, and lower thresholds. ABRs with a vertex-to-tympanic membrane (VT) electrode montage produced a more robust Wave-I, but absent Waves II-IV and higher thresholds. Further study with the VM montage revealed amplitudes that increased with stimulus level and were largest in response to click stimuli, with Wave-II showing the largest ABR amplitude, followed by -IV and -I, with high inter- and intra-subject variability. ABR wave latencies decreased with stimulus level and frequency. When stimulus presentation rate increased or stimuli were presented in close temporal proximity, ABR amplitude decreased, and latency increased. These findings expand upon existing literature of normative clinical physiological data in nonhuman primates and lay the groundwork for future studies investigating the effects of noise-induced pathologies in macaques.
Topics: Animals; Auditory Threshold; Evoked Potentials, Auditory, Brain Stem; Haplorhini; Humans; Macaca; Male; Otoacoustic Emissions, Spontaneous; Reproducibility of Results
PubMed: 35896044
DOI: 10.1016/j.heares.2022.108568