Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 15 de 15
Filter
1.
HNO ; 72(4): 291-302, 2024 Apr.
Article in German | MEDLINE | ID: mdl-38351342

ABSTRACT

Idiopathic sudden sensorineural hearing loss (ISSNHL) is one of the most common diseases in otolaryngology. Its etiology remains unknown. Furthermore, there is only a low level of evidence for the efficacy of established treatment modalities. In addition to systemic glucocorticoids, intratympanic corticosteroid treatment (ICT) has become increasingly important for treatment of ISSNHL. Different application strategies and treatment regimens have been described; however, uniform standards do not yet exist. ICT may be used for primary treatment as well as salvage therapy. Current data from meta-analyses show no benefit of intratympanic versus systemic primary therapy for sudden hearing loss (moderate evidence) but suggest a benefit of intratympanic secondary treatment over no treatment or placebo (high effect size, low evidence). Regarding combination of systemic and local glucocorticoid therapy in primary treatment of hearing loss, there may be a small benefit over systemic treatment alone (low effect size, low evidence).


Subject(s)
Hearing Loss, Sensorineural , Hearing Loss, Sudden , Humans , Glucocorticoids , Hearing Loss, Sudden/diagnosis , Hearing Loss, Sudden/drug therapy , Dexamethasone/therapeutic use , Treatment Outcome , Hearing Loss, Sensorineural/diagnosis , Hearing Loss, Sensorineural/drug therapy , Hearing Loss, Sensorineural/etiology , Adrenal Cortex Hormones/therapeutic use , Injection, Intratympanic , Audiometry, Pure-Tone/adverse effects
2.
Audiol Neurootol ; 28(4): 255-261, 2023.
Article in English | MEDLINE | ID: mdl-36754035

ABSTRACT

INTRODUCTION: The Carhart notch is a well-known sign of stapes fixation. However, previous studies have reported that the Carhart notch is not specific to stapes fixation and is also present in other middle ear diseases. Therefore, this study investigated the diagnostic value of threshold gap between air conduction and bone conduction (ABG) for stapes fixation, instead of the bone conduction dip representing the Carhart notch. METHODS: A total of 199 ears that underwent exploratory tympanotomy were enrolled in this retrospective study. They were categorized into three groups according to surgical findings: stapes fixation (SF), other ossicle fixation (OF), and chain disconnection (CD). Preoperative pure-tone audiograms and impedance audiograms were compared between the groups. RESULTS: The incidence of the Carhart notch did not differ between the groups. The ABG at 2,000 Hz showed a good diagnostic performance for distinguishing between the SF and CD groups (area under the curve, AUC = 0.816, p < 0.001), but poor performance for distinguishing between the SF and OF groups (AUC = 0.662, p = 0.003). Bone conduction at 2,000 Hz showed a moderate performance for distinguishing between the SF and CD groups (AUC = 0.707, p < 0.001) and did not show statistically significant results for distinguishing between the SF and OF groups (AUC = 0.594, p = 0.080). The tympanic membrane compliance was significantly higher in the CD group than in the SF group (p = 0.001). CONCLUSIONS: The Carhart notch was not a specific finding of SF. The sensitivity and specificity of ABG ≤15 dB at 2,000 Hz for distinguishing between SF and CD were 60.4% and 89.2%, respectively. To prepare for surgical interventions in patients with conductive hearing loss but a normal tympanic membrane, clinicians should comprehensively consider these results.


Subject(s)
Otosclerosis , Stapes Surgery , Humans , Stapes , Otosclerosis/surgery , Retrospective Studies , Audiometry, Pure-Tone/adverse effects , Audiometry, Pure-Tone/methods , Auditory Threshold , Stapes Surgery/methods , Hearing Loss, Conductive/diagnosis , Hearing Loss, Conductive/surgery , Hearing Loss, Conductive/etiology , Bone Conduction , Treatment Outcome
3.
Cranio ; 41(2): 173-177, 2023 Mar.
Article in English | MEDLINE | ID: mdl-33003991

ABSTRACT

OBJECTIVE: To evaluate the presence of tinnitus and tinnitus-related hearing loss in individuals with temporomandibular joint disorders. METHODS: In the study, 288 patients with temporomandibular joint complaints and 33 patients with both temporomandibular and tinnitus complaints were evaluated. The Tinnitus Handicap Inventory was used in the evaluation of tinnitus. Pure tone audiometry test was used to evaluate the presence and degree of hearing loss. The Student's t-test and Independent Sample t-test were applied to compare between groups. RESULTS: The incidence of tinnitus was found to be 11.46% among patients with temporomandibular disorders. Tinnitus and tinnitus severity levels were found to have significant differences in patients with temporomandibular disorders. No significant relationships were found between right and left ear pure tone audiometry test results in patients. CONCLUSION: There is a relationship between aural symptoms, tinnitus, and temporomandibular disorders. Patients with temporomandibular disorders should be evaluated for otological symptoms.


Subject(s)
Hearing Loss , Temporomandibular Joint Disorders , Tinnitus , Humans , Tinnitus/complications , Tinnitus/epidemiology , Hearing Loss/complications , Temporomandibular Joint Disorders/complications , Audiometry, Pure-Tone/adverse effects
4.
JNMA J Nepal Med Assoc ; 61(267): 844-847, 2023 Nov 01.
Article in English | MEDLINE | ID: mdl-38289736

ABSTRACT

Introduction: Hearing loss is defined as the partial or total reduction in auditory acuity. Hearing loss can cause detrimental effects on speech, language, developmental, educational, and cognitive outcomes in children. This study aimed to find out the prevalence of hearing loss among children visiting the Department of Otolaryngology and HNS of a tertiary care centre. Methods: A descriptive cross-sectional study was conducted among children visiting the Department of Otolaryngology and HNS between 1 January 2022 and 31 December 2022 after obtaining ethical approval. All the patients who underwent pure tone evaluation were included in the study. A convenience sampling technique was used. The point estimate was calculated at a 95% Confidence Interval. Results: Among 3051 children, 328 (10.75%) (9.65-11.85, 95% Confidence Interval) had hearing loss. Among children with hearing loss, 170 (51.83%) of children were female. The mean age of children with hearing loss was 13.31±3.39 years. The mean pure tone average among 452 ears with hearing loss was 44.60±17.71 dB. The commonest degree of hearing loss was mild hearing loss 266 (58.85%), and the commonest type was conductive hearing loss 310 (68.58%). Among children with hearing loss, 124 (37.80%) had bilateral hearing loss. Conclusions: The prevalence of hearing loss among children visiting the Department of Otolaryngology and HNS was found to be lower than similar studies done in similar settings. Keywords: audiology; audiometry; hearing loss; outpatients; prevalence.


Subject(s)
Hearing Loss , Otolaryngology , Child , Humans , Female , Adolescent , Male , Tertiary Care Centers , Cross-Sectional Studies , Audiometry, Pure-Tone/adverse effects , Audiometry, Pure-Tone/methods , Hearing Loss/epidemiology , Hearing Loss/etiology
5.
Article in Chinese | MEDLINE | ID: mdl-36543395

ABSTRACT

Objective:To analyze the clinical characteristics of unilateral acoustic neuroma(AN) with normal hearing, so as to provide evidence for early identification AN. Methods:Clinical datas from 73 patients of unilateral AN with normal hearing of Otorhinolaryngology Head and Neck Surgery of Beijing Tiantan Hospital affiliated of Capital Medical University from August 2019 to April 2022 admitted to department were retrospectively analyzed. All patients underwent pure tone audiometry(PTA), speech discrimination score(SDS), auditory brainstem response(ABR), distortion product otoacoustic emission(DPOAE) and head enhanced MRI. Results:The incidence of normal hearing among patients with AN was 10.7%. Male∶female=1∶2.2; the mean age of the patients was(37.3±9.4) years; the mean tumor size was(24.2±11.2) mm. Tinnitus was the most common reason for visit; the patients who had headache and dizziness had larger tumors. Surgery was the main treatment, and the patients who underwent surgery had larger tumors than those of follow-up. Heterogeneous tumors were the most common type of MRI, homogeneous tumors were smaller than heterogeneous and cystic tumors. The sensitivity of ABR in the diagnosis of AN with normal hearing was 95.9%, and that of ≥20 mm tumors was 100%; prolonged Ⅴ-waves were the most common, patients with Ⅴ-wave deletion had larger tumors than those with normal or prolonged Ⅴ-waves. Patients who had the longer the Ⅴ-wave and the longer difference between Ⅰ-Ⅴ wave had larger tumors. DPOAE was not elicited at full frequency in 11 patients. There was no statistically significant difference in age among patients with different symptoms, treatments, types of MRI, ABR and DPOAE. Conclusion:AN of normal hearing was most common in 30-39 years old women. Patients had different symptoms, phenotypes of MRI and ABR. Patients with normal hearing who had tinnitus, dizziness, headache, facial paraesthesia, and recovery after sudden haring loss can be further examination of ABR and DPOAE for early identification AN. The sensitivity of ABR in diagnosis of hearing normal AN was 95.9%, and the abnormal type of Ⅴ-wave is related to tumor size.


Subject(s)
Neuroma, Acoustic , Tinnitus , Female , Humans , Tinnitus/diagnosis , Neuroma, Acoustic/diagnosis , Neuroma, Acoustic/complications , Neuroma, Acoustic/pathology , Retrospective Studies , Dizziness/complications , Auditory Threshold , Hearing , Evoked Potentials, Auditory, Brain Stem , Vertigo/complications , Audiometry, Pure-Tone/adverse effects
6.
Orv Hetil ; 163(42): 1682-1689, 2022 Oct 16.
Article in Hungarian | MEDLINE | ID: mdl-36244011

ABSTRACT

Introduction: Tinnitus is a sound without an external sound stimulus, usually only perceived by the sufferer. Inner ear damage might be found in its background, although many other possible causes exist. Therefore, there is a need for a detailed examination in all cases. Method: In the present investigation, 100 patients (38 men, 62 women; mean age +/- SD: 59 years +/- 11.3) suffering from tinnitus were enrolled. The data and examination results of these patients were analysed in detail. The outcomes of the brain MRI, carotid-vertebral ultrasound, cervical X-ray, pure-tone audiometry, and tinnitometry were analyzed regarding the detailed examinations. Results: In terms of tinnitus laterality, left-sided (34%) and both-sided (53%) were the most frequent ones. The frequency of the examinations was the following: audiometry and tinnitometry (100%), cervical X-ray (80%), cerebral MRI (76%) and carotid-vertebral Doppler ultrasound (21%). Cervical spondylosis/spondyloarthrosis (69 patients), vascular encephalopathy (56 patients) and atherosclerosis of the carotid artery (20 patients) were observed as the most common aberrations. Using the audiometry, normal hearing was detected in 14%, slight sensorineural hearing loss in 25%, moderate sensorineural hearing loss in 44% and severe sensorineural hearing loss in 17%. Tinnitometry detected tinnitus with a mean frequency of 4200 +/- 2200 Hz and intensity of 40 +/- 14.4 dB. Conclusion: The detailed examination of patients suffering from tinnitus is essential in multidisciplinary therapy planning. Possible complications in other organs can also be detected using the carotid-vertebral ultrasound as screening method. Based on the cervical X-ray, the somatosensory tinnitus form can be observed. Pure-tone audiometry and tinnitometry help detect hearing loss combined with tinnitus, pitch, and loudness, which are also essential in therapy planning.


Subject(s)
Hearing Loss, Sensorineural , Hearing Loss , Tinnitus , Acoustic Stimulation , Audiometry, Pure-Tone/adverse effects , Audiometry, Pure-Tone/methods , Female , Hearing Loss, Sensorineural/diagnosis , Humans , Male , Tinnitus/diagnosis , Tinnitus/etiology , Tinnitus/therapy
7.
Article in English | MEDLINE | ID: mdl-35886649

ABSTRACT

Background: A high level of occupational noise exposure has been noted in the fishing sector. Yet, less is known regarding other navigation groups, such as merchant seafarers, since a French study in the 1980s. This study assesses hearing impairment (HI) in a French merchant seafarers' population. Methods: We collected data of all audiograms performed in 2018 and 2019 for French merchant seafarers. For each seafarer, hearing ability was measured in both ears using pure-tone audiometry at the following frequencies: 0.5, 1, 2, 3, 4, 6, and 8 kHz. Hearing threshold levels (HTLs), or the intensity of sound below which no sound is detected, were measured in decibels Sound Pressure Level (dB SPL) at each frequency and recorded in 5 dB increments. For HI, we used the validated definition of the American Speech−Language−Hearing Association (ASHA). Results: We were able to include statistical analysis results of 8308 audiograms. In a multiple logistic regression adjusted for age, experience, and class of navigation, we found that experience of more than 14 years Odds Ratio OR 1.28 (CI 95% 1.07−1.53), age 31−40 OR 2.2 (CI 95% 1.4−3.4), and >40 years OR 14, 3 (IC 95% 9.7−21) and marine engineers OR 1.26 (IC 95% 1.01−1.57) were still risk factors for HI. Conclusion: In 2018, Marine engineers were still the workers' group with a higher risk of HI in merchant seafarers but, notch at 4 Hz, specific of noise-induced hearing loss, has improved. They have an HI close to the definition of socioacousis and mean deficit differences with deck and services' merchant seafarers improved. Our results could be interpreted as a limitation of occupational noise exposure impact in a merchant seafarers' population, needing an improvement in prevention measures and also encouraged to continue to improve onboard working conditions.


Subject(s)
Hearing Loss, Noise-Induced , Occupational Diseases , Adolescent , Adult , Audiometry, Pure-Tone/adverse effects , Hearing , Hearing Loss, Noise-Induced/diagnosis , Hearing Loss, Noise-Induced/epidemiology , Hearing Loss, Noise-Induced/etiology , Humans , Occupational Diseases/epidemiology , Retrospective Studies , Risk Factors
8.
Front Public Health ; 10: 852556, 2022.
Article in English | MEDLINE | ID: mdl-35651868

ABSTRACT

Objective: Otitis media is a recognized cause of significant hearing loss, particularly in developing countries. This study aimed to investigate the relationship between otitis media and hearing loss in Chinese adults aged 18 years and older. Methods: The survey was based on WHO Ear and Hearing Disorders Survey Protocol and 36,783 adults at the ages between 18 years and above were selected in this study. Trained local examiners performed pure tone audiometry to screen people with hearing loss, and those who were screened positively for hearing loss were referred to audiologists to make final diagnosis. All participants underwent clinical ENT check-up and otoscopic examination by doctors trained in ENT. Each participant was assigned a single middle ear diagnosis. Diagnoses were assigned as per the WHO classification of ear and hearing disorders. Results: Logistic regressions showed that higher prevalence of hearing loss was found in participants with otitis media, with an unadjusted odds ratio of 5.67 (95%CI: 4.66, 6.90). The next two models (Model 2-3) had slight impact on ORs. The interaction of residency and otitis media was statistically significant (OR = 1.70, 95%CI = 1.15, 2.53); otitis media patients in rural areas had higher risk of hearing loss. However, this interaction became not significant in 65 years old and above participants. Conclusions: Otitis media was associated with the risk of hearing loss. Compared with urban patients with otitis media, rural patients have the higher risk of hearing loss. Action to reduce the risk of hearing loss in otitis media will require attention to rural-urban disparities.


Subject(s)
Hearing Loss , Otitis Media , Adolescent , Adult , Aged , Audiometry, Pure-Tone/adverse effects , Audiometry, Pure-Tone/methods , China/epidemiology , Hearing Disorders/complications , Hearing Disorders/diagnosis , Hearing Loss/epidemiology , Hearing Loss/etiology , Humans , Otitis Media/complications , Otitis Media/epidemiology
9.
BMC Res Notes ; 15(1): 228, 2022 Jun 27.
Article in English | MEDLINE | ID: mdl-35761410

ABSTRACT

OBJECTIVE: Hearing loss is an important public health problem. Its causes vary, including infections, noise, and aging. The first wave of the COVID-19 pandemic occurred in April 2020 in Japan. During the pandemic, people were urged to stay at home and drastically changed their lifestyles. This study aimed to examine hearing loss before and during the pandemic. The prevalence during the pandemic after April 2020 was compared for the period in 2019. Study subjects were those who received health checkups in both periods. Hearing loss was defined as a hearing threshold of > 30 dB at 1 kHz and > 40 dB at 4 kHz in either ear using pure-tone audiometry. RESULTS: A total of 2367 persons presented in both 2019 and 2020. The overall rates of hearing loss were 9.5% and 13.2% before and after the pandemic, respectively. After controlling for age, sex, current smoking, regular exercise and alcohol consumption, the rate of hearing loss showed a significant increase in 2020 (p = < 0.0001). With age stratification, an increase was observed in the participants aged < 40 years (1.3% vs. 3.1%, p < 0.001) and 40-59 years (7.2% vs. 12.6%, p < 0.001). Further studies are needed to confirm the impact of the COVID-19 pandemic on hearing loss.


Subject(s)
COVID-19 , Hearing Loss , Aging , Audiometry, Pure-Tone/adverse effects , COVID-19/epidemiology , Hearing Loss/epidemiology , Hearing Loss/etiology , Humans , Pandemics
10.
Antioxid Redox Signal ; 36(16-18): 1171-1202, 2022 06.
Article in English | MEDLINE | ID: mdl-34346254

ABSTRACT

Significance: Noise-induced hearing loss (NIHL) is an important public health issue resulting in decreased quality of life for affected individuals, and significant costs to employers and governmental agencies. Recent Advances: Advances in the mechanistic understanding of NIHL have prompted a growing number of proposed, in-progress, and completed clinical trials for possible protections against NIHL via antioxidants and other drug agents. Thirty-one clinical trials evaluating prevention of either temporary or permanent NIHL were identified and are reviewed. Critical Issues: This review revealed little consistency in the noise-exposed populations in which drugs are evaluated or the primary outcomes used to measure NIHL prevention. Changes in pure-tone thresholds were the most common primary outcomes; specific threshold metrics included both average hearing loss and incidence of significant hearing loss. Changes in otoacoustic emission (OAE) amplitude were relatively common secondary outcomes. Extended high-frequency (EHF) hearing and speech-in-noise perception are commonly adversely affected by noise exposure but are not consistently included in clinical trials assessing prevention of NIHL. Future Directions: Multiple criteria are available for monitoring NIHL, but the specific criterion to be used to define clinically significant otoprotection remains a topic of discussion. Audiogram-based primary outcome measures can be combined with secondary outcomes, including OAE amplitude, EHF hearing, speech-in-noise testing, tinnitus surveys, and patient-reported outcomes. Standardization of test protocols for the above primary and secondary outcomes, and associated reporting criterion for each, would facilitate clinical trial design and comparison of results across investigational drug agents. Antioxid. Redox Signal. 36, 1171-1202.


Subject(s)
Ear, Inner , Hearing Loss, Noise-Induced , Audiometry, Pure-Tone/adverse effects , Auditory Threshold , Drugs, Investigational , Hearing Loss, Noise-Induced/drug therapy , Hearing Loss, Noise-Induced/epidemiology , Hearing Loss, Noise-Induced/prevention & control , Humans , Quality of Life
11.
Auris Nasus Larynx ; 49(2): 195-201, 2022 Apr.
Article in English | MEDLINE | ID: mdl-34304942

ABSTRACT

OBJECTIVE: Adenoid hypertrophy (AH) has been identified as a cause of otitis media with effusion (OME), which is the most common cause of childhood hearing loss. Indeed, there may be other upper airway-related predisposing factors such as, location of the adenoid, accompanying tonsillar hypertrophy (TH) and nasal septal deviation (NSD) for the development of OME. In this study, we aimed to evaluate the associations between the upper airway physicals and OME with auditory functions. METHODS: Eighty-six ears of 43 children, aged 3-11 years were included in this prospective clinical study. Findings of otolaryngologic examinations were noted. Data of pure tone audiometry (PTA), traditional tympanometry (TT) and wideband tympanometry (WBT) parameters were collected. Cluster analysis was performed to the following variables: age, sex; the adenoid choana percentage (ACP), the presences of adenoid around torus tubarius (AATT), TH, NSD and OME; peak pressure (PP) values on TT, resonance frequencies (RF) on WBT, ambient pressure absorbance ratios (APAR) and PTA hearing thresholds. RESULTS: Two groups of ears revealed by clustering; cluster-1 (n = 46) and cluster-2 (n = 40), at the similarity level of 0.662. The presences of AH, AATT, OME and the medians of ACP, PP, RF, WBT APARs at all frequencies except 5656 Hz and 8000 Hz, all PTA thresholds were significantly different between two clusters (p < 0.05). The lower WBT APARs and higher PTA thresholds were associated with higher levels of ACP and higher frequencies of the presence of AATT and OME in cluster-1. CONCLUSION: There are associations between AH, AATT and OME together with decline in hearing and SEA. Whereas, TH and NSD are not related to the formation of clusters and they are insignificant factors.


Subject(s)
Otitis Media with Effusion , Audiometry, Pure-Tone/adverse effects , Child , Child, Preschool , Cluster Analysis , Hearing , Humans , Otitis Media with Effusion/complications , Prospective Studies
12.
Am J Audiol ; 26(3): 226-232, 2017 Sep 18.
Article in English | MEDLINE | ID: mdl-28810267

ABSTRACT

PURPOSE: The aim of this study was to assess the proportion of patients seen in a tinnitus and hyperacusis therapy clinic for whom presentation levels based on the British Society of Audiology (BSA)-recommended procedures for pure-tone audiometry and determination of uncomfortable loudness levels (ULLs) exceed ULLs, leading to discomfort during administration of these procedures. METHOD: This was a retrospective cross-sectional study of 362 consecutive patients who attended a National Health Service audiology clinic for tinnitus and/or hyperacusis rehabilitation. RESULTS: For 21% of the patients, presentation levels based on the BSA procedure for pure-tone audiometry exceeded the ULL for at least 1 of the measured frequencies (excluding the first frequency tested, 1 kHz): 0.25, 0.5, 2, 3, 4, 6, and 8 kHz. For 24% of patients, the starting presentation level of 60 dB hearing level recommended for determination of ULLs exceeded the ULL for at least 1 frequency. CONCLUSION: The starting presentation levels used for pure-tone audiometry and measurement of ULLs should be lower than those recommended by the BSA for people with tinnitus and hyperacusis.


Subject(s)
Audiometry, Pure-Tone/adverse effects , Hyperacusis/diagnosis , Pain, Procedural/epidemiology , Tinnitus/diagnosis , Adult , Aged , Cross-Sectional Studies , Female , Humans , Incidence , Loudness Perception , Male , Middle Aged , Pain, Procedural/etiology , Patient Acceptance of Health Care , Retrospective Studies , United Kingdom/epidemiology
13.
J Laryngol Otol ; 121(10): 943-6, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17419898

ABSTRACT

OBJECTIVE: To evaluate the role of otoacoustic emission in children with middle-ear effusion and grommets. MATERIALS AND METHODS: A prospective study was carried out on a total of 90 ears. All children listed for grommet insertion had a pre-operative and post-operative (three to six months after grommet insertion) pure tone audiometry, tympanometry and otoacoustic emission recorded. A comparison was made between pure tone audiometry and otoacoustic emission both pre-operatively and post-operatively. RESULTS: Pre-operatively, 63 ears had an abnormal pure tone audiometry of which 59 had absent otoacoustic emission. Therefore the sensitivity of otoacoustic emission in detecting a conductive loss was 59/63 = 94 per cent (95 per cent confidence interval 85 to 98 per cent). All 27 ears with normal hearing pre-operatively had normal otoacoustic emission. The specificity of otoacoustic emission was 27/27 = 100 per cent, (95 per cent confidence interval, 88 to 100 per cent). The positive predictive value was 59/59 = 100 per cent (95 per cent confidence interval, 94 to 100 per cent). After three to six months all post-operative patients with grommets had a normal pure tone audiometry and otoacoustic emission. So both pure tone audiometry and otoacoustic emission were strongly related both in patients with middle-ear effusion and in patients with grommets. CONCLUSION: As the demonstration of hearing in young and difficult-to-test children can be problematic and time-consuming, we suggest that otoacoustic emission can be used as an alternative to pure tone audiometry in patients with middle-ear effusion and grommets.


Subject(s)
Audiometry, Pure-Tone/methods , Otitis Media with Effusion/physiopathology , Otoacoustic Emissions, Spontaneous/physiology , Audiometry, Pure-Tone/adverse effects , Child , Female , Humans , Male , Middle Ear Ventilation/methods , Otitis Media with Effusion/therapy , Prospective Studies , Sensitivity and Specificity , Treatment Outcome
14.
J Acoust Soc Am ; 102(1): 441-50, 1997 Jul.
Article in English | MEDLINE | ID: mdl-9228806

ABSTRACT

Cochlear microphonics were recorded in response to Gaussian noise from the round window of Mongolian gerbils. A nonlinear systems identification procedure provided the frequency-domain parameters of a third-order polynomial equation describing cochlear mechano-electric transduction (MET). Exposure to an 8 kHz pure tone at 100 dB SPL for 20 min reduced the magnitude of the linear, quadratic, and cubic terms significantly. Animals exposed to a 1- or 4-kHz pure tone showed changes in the quadratic term. Differentiation of the polynomial equation and algebraic manipulations of the coefficients provided physiologic indices of MET. The sensitivity, saturation voltages, and sound pressures required to saturate MET were altered in animals exposed to an 8-kHz pure tone. Limited changes occurred in animals exposed to a 1- or 4-kHz pure tone.


Subject(s)
Audiometry, Pure-Tone/adverse effects , Cochlea/physiopathology , Cochlear Diseases/etiology , Cochlear Diseases/physiopathology , Electric Stimulation , Animals , Auditory Threshold , Gerbillinae
SELECTION OF CITATIONS
SEARCH DETAIL
...