Magnitude of medial olivocochlear reflex assayed by tone-burst-evoked otoacoustic emissions: reliability and comparison with click-evoked emissions.

OBJECTIVE: The purpose of this pilot study was to evaluate the magnitude of the medial olivocochlear reflex (MOCR) estimated by the reduction in tone-burst evoked otoacoustic emissions (TBOAEs) measured at three levels and at three frequencies in response to fixed contralateral white noise. Results were compared with commonly used click-evoked otoacoustic emissions (CEOAEs). DESIGN: TBOAEs and CEOAEs, with and without contralateral 60 dB SPL white noise, were measured in response to stimulation at 55, 65, and 75 dB peSPL. In each subject, the set of measurements was performed twice. Of particular interest were the MOCR and its repeatability. STUDY SAMPLE: 15 normally hearing persons (13 women, average age 32.3 years, SD = 8.1). RESULTS: For both CEOAE and TBOAEs, the reliability of the MOCR was much better for broadband measurements than for half-octave-band filtered estimates. At the same time, the reliability of MOCR in half-octave bands was higher for TBOAEs than for CEOAEs, especially at 2 and 4 kHz. CONCLUSIONS: For general applications where broadband MOCR is of interest, the highest magnitude and reliability is provided by CEOAEs. However, TBOAEs may be better if a particular frequency band is of interest.

Contralateral suppression of transient evoked otoacoustic emissions in adults: A normative study.

BACKGROUND:  Whilst otoacoustic emission (OAE) testing has proved to be valuable in revealing information about cochlear outer hair cell integrity, it does not provide insight into the afferent and efferent pathways once the stimulus has reached neural receptors. This information can be obtained objectively through contralateral acoustic stimulation (CAS) suppression. However, obtaining normative data is essential in the implementation of such tests. OBJECTIVES:  The primary aim was to undertake a small pilot study to collect the CAS suppression across a predefined frequency range in order to provide a preliminary normative data set to be used with the newly developed transient evoked otoacoustic emission (TEOAE)-CAS module (PATH MEDICAL, Germering, Germany). Secondary aims included the analysis of the relationships between left and right CAS suppression, between male and female CAS suppression and between TEOAE signal-to-noise ratio (SNR) and CAS suppression. METHODS:  The purpose of this study was to determine preliminary normative data for contralateral TEOAE suppression from 40 normal ears of 20 healthy young adults (10 males and 10 females). Subjects were recruited using purposive sampling. The CAS suppression responses were obtained automatically by means of the data-collection protocol on the device used. From the data obtained, correlations between TEOAE SNR and CAS suppression were made using Pearson's correlation coefficient. RESULTS:  The data were statistically processed to form a normative database which possesses the potential of serving as a basis for further research aimed at determining the utility of CAS suppression testing when evaluating ear pathology. A mean CAS suppression of 0.8 decibels (dB) (0.61 SD) was obtained. There was no statistically significant relationship between TEOAE SNR and CAS suppression. There was no significant suppression difference in terms of laterality of ears or gender. CONCLUSION:  Normative values for CAS suppression of TEOAEs in a group of normal-hearing individuals were obtained using the newly developed TEOAE-CAS module (PATH MEDICAL, Germering, Germany). The availability of normative data for contralateral TEOAE suppression using the studied module allows for it to become commercially available, which will enable researchers and audiologists to perform this measurement in different populations in the evaluation of ear pathology.

Contralateral Suppression of Transient-evoked Otoacoustic Emissions in Leisure Noise Exposed Individuals.

Background: Leisure noise may have a significant impact on hearing thresholds and young adults are often exposed to loud music during leisure activities. This behavior puts them at risk of developing noise-induced hearing loss (NIHL). A frequent initial indication of NIHL is reduced hearing acuity at 4 kHz. The objective of the current study was to assess the role of the medial olivocochlear reflex (MOCR) in leisure noise-exposed individuals with and without a 4-kHz notch. Materials and Methods: Audiological evaluation, including pure-tone and immittance audiometry, was performed for 156 college-going, young adults between May 2019 to December 2019. All participants had averaged pure-tone audiometric thresholds within normal limits, bilaterally. Annual individual exposure to personal listening devices (PLDs) was calculated using the Noise Exposure Questionnaire. The participants were then categorized into exposed (with and without audiometric 4 kHz notch) and nonexposed groups. Transient-evoked otoacoustic emission amplitude and its contralateral suppression were measured using linear and nonlinear click stimuli to study the effect of leisure noise exposure on MOCR. Results: A significantly reduced overall contralateral suppression effect in participants exposed to PLD usage (P = 0.01) in both linear and nonlinear modes. On the contrary, significantly increased suppression was observed in linear mode for the 4 kHz frequency band in the PLD-exposed group without an audiometric notch (P = 0.009), possibly suggesting an early biomarker of NIHL. Conclusion: Measuring contralateral suppression of otoacoustic emissions may be an effective tool to detect early NIHL in leisure noise-exposed individuals.

Evaluation of the hearing status in carpenters.

PURPOSE: Carpenters are constantly exposed to a noise level of 82-100 dB(A) in their professional lives. The aim of this study is to evaluate the hearing status of carpenters with pure -tone audiometry and transient evoked otoacoustic emissions test. METHODS: A total of 62 individuals were enrolled. The study group consisted of 31 carpenters and the controls were age and sex matched healthy individuals who were not exposed to continuous or sudden noise. RESULTS: The average age of the carpenters is 44.58 ± 10.33, the average age of the control group is 41.84 ± 8.65 and there was no statistically significant difference (p = 0.262). There was a significant hearing loss in the study group nearly at all frequencies when compared to the control group (p < 0.05). The emission values of the right and left ears of the carpenters were significantly lower than the controls at 2000 and 2800 Hz (p < 0.05). CONCLUSION: Accordingly, carpenters seem to be susceptible to the development of noise-induced hearing loss.

Prenatal Exposure to Tobacco and Alcohol Alters Development of the Neonatal Auditory System.

Prenatal exposures to alcohol (PAE) and tobacco (PTE) are known to produce adverse neonatal and childhood outcomes including damage to the developing auditory system. Knowledge of the timing, extent, and combinations of these exposures on effects on the developing system is limited. As part of the physiological measurements from the Safe Passage Study, Auditory Brainstem Responses (ABRs) and Transient Otoacoustic Emissions (TEOAEs) were acquired on infants at birth and one-month of age. Research sites were in South Africa and the Northern Plains of the U.S. Prenatal information on alcohol and tobacco exposure was gathered prospectively on mother/infant dyads. Cluster analysis was used to characterize three levels of PAE and three levels of PTE. Repeated-measures ANOVAs were conducted for newborn and one-month-old infants for ABR peak latencies and amplitudes and TEOAE levels and signal-to-noise ratios. Analyses controlled for hours of life at test, gestational age at birth, sex, site, and other exposure. Significant main effects of PTE included reduced newborn ABR latencies from both ears. PTE also resulted in a significant reduction of ABR peak amplitudes elicited in infants at 1-month of age. PAE led to a reduction of TEOAE amplitude for 1-month-old infants but only in the left ear. Results indicate that PAE and PTE lead to early disruption of peripheral, brainstem, and cortical development and neuronal pathways of the auditory system, including the olivocochlear pathway.

Pure-Tone Hearing Thresholds and Otoacoustic Emissions in Students of Music Academies.

The objective of this study was to assess the hearing of music students in relation to their exposure to excessive sounds. A standard pure-tone audiometry, transient-evoked otoacoustic emissions (TEOAEs) and distortion-product otoacoustic emissions (DPOAEs) were determined in 163 students of music academies, aged 22.8 ± 2.6 years. A questionnaire survey and sound pressure level measurements during solo and group playing were also conducted. The control group comprised 67 subjects, mainly non-music students, aged 22.8 ± 3.3 years. Study subjects were exposed to sounds at the A-weighted weekly noise exposure level (LEX,w) from 75 to 106 dB. There were no significant differences in the hearing thresholds between groups in the frequency range of 4000-8000 Hz. However, music students compared to control group exhibited lower values of DPOAE amplitude (at 6000 and 7984 Hz) and signal-to-noise ratio (SNR) (at 984, 6000, and 7984 Hz) as well as SNR of TEOAE (in 1000 Hz band). A significant impact of noise exposure level, type of instrument, and gender on some parameters of measured otoacoustic emissions was observed. In particular, music students having LEX,w ≥ 84.9 dB, compared to those with LEX,w < 84.9 dB, achieved significantly lower DPOAE amplitude at 3984 Hz. Meanwhile, both TEOAE and DPOAE results indicated worse hearing in students playing percussion instruments vs. wind instruments, and wind instrument players vs. students playing stringed instruments.

Transient-evoked otoacoustic emission signals predicting outcomes of acute sensorineural hearing loss in patients with Ménière's disease.

Background: Fluctuating hearing loss is characteristic of Ménière's disease (MD) during acute episodes. However, no reliable audiometric hallmarks are available for counselling the hearing recovery possibility.Aims/objectives: To find parameters for predicting MD hearing outcomes.Material and methods: We applied machine learning techniques to analyse transient-evoked otoacoustic emission (TEOAE) signals recorded from patients with MD. Thirty unilateral MD patients were recruited prospectively after onset of acute cochleo-vestibular symptoms. Serial TEOAE and pure-tone audiogram (PTA) data were recorded longitudinally. Denoised TEOAE signals were projected onto the three most prominent principal directions through a linear transformation. Binary classification was performed using a support vector machine (SVM). TEOAE signal parameters, including signal energy and group delay, were compared between improved (PTA improvement: ≥15 dB) and nonimproved groups using Welch's t-test.Results: Signal energy did not differ (p = .64) but a significant difference in 1-kHz (p = .045) group delay was recorded between improved and nonimproved groups. The SVM achieved a cross-validated accuracy of >80% in predicting hearing outcomes.Conclusions and significance: This study revealed that baseline TEOAE parameters obtained during acute MD episodes, when processed through machine learning technology, may provide information on outer hair cell function to predict hearing recovery.

[Age-related changes of otoacoustic emission]. / Vozrastnye izmeneniia otoakusticheskoi émissii.

The aim of the study was to assess age-related changes of the transient evoked otoacoustic emissions (TEOAE) and distortion product otoacoustic emissions (DPOAE) as well as to evaluate age-related changes of DPOAE suppression in adult subjects with normal hearing and presbycusis. Only women participated in the study: 26 young women with normal hearing (20-31 years old) were included into the first group; the second group consisted of 28 elderly (60-74 years old) with normal hearing; the third group included 28 elderly women with presbycusis (mild-to-moderate hearing loss). Age-related decrease of prevalence and amplitude of OAEs was proved to be significant; no significant differences of these data for left and right ears were revealed. Contralateral suppression of DPOAE was noted more often and was the greatest in young listeners and was presented in all frequency range, meanwhile the suppression was minimal and rarely noted in patients with presbycusis. The DPOAE amplitude enhancement in the contralateral noise condition was recorded in all groups of listeners, more often in aged patients both with normal hearing and hearing loss. These results may indicate age-related changes of medial olivocochlear complex, which take place not only in patients with hearing loss but in normal hearing subjects as well.. The findings were confirmed by the results of acoustic reflex measurements obtained in this study.

Trigonelline promotes auditory function through nerve growth factor signaling on diabetic animal models.

BACKGROUND: Protection of cochlear function and reconstruction of neuronal networks in damaged auditory sensory structures is crucial for therapeutic treatment of diabetic hearing loss. Nerve growth factor (NGF) has been used as a novel therapeutic target to protect against the neurodegenerative effects of Diabetes Mellitus (DM). PURPOSE: We aimed to evaluate the potential effect of trigonelline (TRG) on reducing auditory damage produced by DM using NGF as a potential marker. METHOD: Docking simulations were carried out using Autodock Vina software and visualized using Discovery Studio. Morphological analysis of hair cells and neuromasts was performed on alloxan-induced diabetic zebrafish by fluorescence and scanning electron microscopy. Blockage of NGF receptor phosphorylation with K-252a was used to evaluate TRG and NGF action. Further assessment of NGF by ELISA on a primary culture of spiral ganglion cells was performed as a marker of neuronal function on the hearing system. Finally, auditory function was assessed in LepR(db/db) mice using auditory brainstem response (ABR) and transient evoked otoacoustic emission (TEOAE) during 8 weeks. RESULTS: Docking simulations showed that TRG binds to the active site of NGF through molecular interactions with Lysine88 (Lys88) and Tyrosine52 (Tyr52). TRG treatment significantly reduced hair cell loss and neuromast damage in diabetic zebrafish (P < .05). Further evaluation revealed a significant increase in the number of neuromasts after NGF administration (P < .001). TRG and NGF action was suppressed during blockage of NGF receptor phosphorylation. Moreover, spiral ganglion cells revealed significant elevation on NGF values after TRG treatment (P < .05). In vivo evaluation of LepR(db/db) mice revealed a significant reduction in the auditory damage produced under diabetic progression, characterized by reduced ABR hearing threshold shifts and increased signal-to-noise ratio in TEOAE (P < .05). CONCLUSIONS: This study suggests that the enhanced hearing function produced by TRG may be mediated by NGF, providing a potential therapeutic strategy for diabetic hearing loss.

Medial olivocochlear function in children with poor speech-in-noise performance and language disorder.

OBJECTIVES: Contralateral masking of transient-evoked otoacoustic emissions is a phenomenon that suggests an inhibitory effect of the olivocochlear efferent auditory pathway. Many studies have been inconclusive in demonstrating a clear connection between this system and a behavioral speech-in-noise listening skill. The purpose of this study was to investigate the activation of a medial olivocochlear (MOC) efferent in children with poor speech-in-noise (PSIN) performance and children with language impairment and PSIN (SLI + PSIN). METHODS: Transient evoked otoacoustic emissions (TEOAEs) with and without contralateral white noise were tested in 52 children (between 6 and 12 years). These children were arranged in three groups: typical development (TD) (n = 25), PSIN (n = 14) and SLI + PSI (n = 13). RESULTS: PSIN and SLI + PSI groups presented reduced otoacoustic emission suppression in comparison with the TD group. CONCLUSION: Our finding suggests differences in MOC function among children with typical development and children with poor SIN and language problems.

[Issues Related to Screening and Caring for Newborns With Hearing Impairments].

The critical period for auditory development in humans begins at around the 20th gestational week and continues until 3 years of age. Both genetic and environmental factors are known to cause impaired hearing. Without early identification and intervention, hearing-impaired children face a high risk of experiencing significant difficulties with speech and language development, social behavior, and emotional functioning. Two types of commonly used hearing screening technologies include transient evoked otoacoustic emission (TEOAE) and automated auditory brainstem response (aABR). aABR is considered to have high sensitivity and specificity, to have a relatively low referral rate, and to generate a relatively low rate of false-positive results in identifying newborn hearing impairment. The present paper outlines the psychosocial issues that are commonly experienced by parents of hearing-impaired children. Parents and other family members may benefit from medical, financial, social, and education supports in order to facilitate their adjustment to this challenging situation. The relevant literature is reviewed and recommendations for improving care for this population are provided.

The evaluation of cochlear functions in Familial Mediterranean Fever.

Familial Mediterranean Fever (FMF) is a progressive disease characterized by chronic inflammation, which also has negative effects on cochlear functions and hearing levels. We investigated whether the cochlear functions and hearing levels of FMF patients were different than healthy controls and also evaluated the relationship of hearing levels with the age at diagnosis, duration without treatment, and inflammation and lipid parameters in this study. A total of 60 patients diagnosed with FMF and 48 age, gender and body mass index (BMI)-matched healthy controls were included in the study. The hemogram, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and lipid parameters of the subjects were studied and they all underwent pure tone audiometry and Transient evoked otoacoustic emission tests after an otologic examination. The hearing levels of the FMF group were significantly higher than those of the control group. The TEOAE signal/noise (S/N) ratios were similar in both groups. A positive relationship was present between the audiometric test results and the age, BMI, low-density lipoprotein and triglyceride levels and a negative relationship with the high-density lipoprotein levels. A negative relationship was present between the TEOAE S/N ratios and the age of the patients, duration without treatment, lipid parameters, inflammation markers and the creatinine level. FMF patients are exposed to chronic inflammation and this can influence their hearing levels. The age at diagnosis, duration without treatment, chronic inflammation, unfavorable lipid parameters, and obesity can affect hearing tests negatively.

The effects of hypotensive anaesthesia on otoacoustic emissions: a prospective, randomized, double-blind study with objective outcome measures.

The aim of the present study was to compare pre- and post-operative otoacoustic emission examinations of patients who experienced surgery under hypotensive anaesthesia using distortion product otoacoustic emission (DPOAE) and transient evoked otoacoustic emission (TEOAE). Forty-one patients, admitted to our tertiary centre for nasal valve surgery, were prospectively and randomly assigned into two groups. Hypotensive group included 20 patients, while control group included 21 patients. All investigators and patients were blinded to anaesthesia assignment throughout the course of the study. DPOAEs and TEOAEs were performed before surgery and repeated after 15 days in both groups. In control group, DPOAE-DP1 levels per frequency increased significantly in the post-operative period when compared with the pre-operative values in all patients. However, DPOAE-DP1 levels decreased significantly in hypotensive group. Similarly, DPOAE-SNR levels per frequency decreased significantly in hypotensive group. In conclusion, we have observed that under the influence of hypotensive general anaesthesia, the amplitudes of OAEs are affected.

Exposure to excessive sounds during orchestra rehearsals and temporary hearing changes in hearing among musicians.

BACKGROUND: It has been shown that musicians are at risk of noise-induced hearing loss. The aim of the study has been to evaluate the temporary changes of hearing in the case of orchestral musicians after group rehearsals. MATERIAL AND METHODS: The study group comprised 18 orchestral musicians, aged 30-58 years old (mean: 40 years old) having 12-40 years (mean: 22 years) of professional experience. The temporary changes in hearing after group rehearsals were determined using transient-evoked otoacoustic emissions (TEOAEs). Noise exposures during group rehearsals were also evaluated. RESULTS: Musicians' hearing threshold levels were higher (worse) than expected for the equivalent non-noise-exposed population. Moreover, the high frequency notched audiograms were observed in some of them. After rehearsals, during which musicians were exposed to orchestral noise at A-weighted equivalent-continuous sound pressure level (normalized to 8-h working day) varied from 75.6-83.1 dB (mean: 79.4 dB). The significant post-exposure reductions of TEOAE amplitudes (approx. 0.7 dB) both for the total response and frequency bands of 2000 and 3000 Hz were noted. However, there were no significant differences between pre- and postexposure reproducibility of TEOAE. CONCLUSIONS: Obtained results have confirmed that orchestral musicians are at risk of hearing loss due to their professional activities, even at exposures to orchestral noise less than the limit values for occupational noise.

Vestibular evoked myogenic potentials in pediatric patients with familial Mediterranean fever.

OBJECTIVES: We aimed to investigate whether the chronic autoinflammatory process in familial Mediterranean fever (FMF), which affects numerous systems, results in vestibular dysfunction in pediatric patients being followed up for diagnosis of FMF using VEMP recordings. METHODS: 30 patients (60 ears) diagnosed with FMF and 20 (40 ears) healthy volunteers were included in the study. Following routine ear, nose, and throat examination, transient-evoked otoacoustic emissions (TEOAE) and vestibular-evoked myogenic potential (VEMP) tests were performed. RESULTS: A total of 30 FMF pediatric patients (13 male, 17 female) and 20 controls (8 male, 12 female) were included in the study. The mean age of FMF patients was 12.13 ± 2.88 years, while that of the controls was 12.90 ± 2.80 years. All of the otoacoustic emission results of the patient and control groups were "pass VEMP recordings received in both ears of patients with FMF (60 ears) and both ears of controls (40 ears). There was no statistically significant difference for latencies or amplitudes for either patients or controls (p > 0.05). CONCLUSION: In order to research the effect of FMF on vestibular functions, we measured VEMP. However, we did not detect alterations of VEMP in FMF patients.

Hearing impairment and its risk factors by newborn screening in north-western India.

BACKGROUND: To screen the newborn by Transient evoked Otoacoustic emission and to assess the incidence of hearing damage and associated risk factors. METHOD: This longitudinal prospective observational study was conducted at a tertiary care hospital in India. A total of 415 babies were included in the study. All the newborns were evaluated with Transient evoked Otoacoustic emission (TEOAE) which was done by age of 1-3 days. Auditory brain stem response audiometry (AABR) was performed at the age of three months for confirming the hearing loss in the neonates those who failed the TEOAE screening. For infants proven to have significant hearing loss in one or both ears, were denoted to an ear, nose, and throat specialist for further evaluation & rehabilitation. RESULTS: Out of total 415 babies included in the study, 22 neonates showed abnormal TEOAE examination. Out of these 22 neonates, hearing loss was confirmed in 18 (82 %) subjects. by AABR. The following antenatal and post-natal risk factors were associated with hearing loss: ante-partum bleeding, history of maternal blood transfusion, fetal distress, prematurity, severe birth asphyxia, NICU admission for more than 24 h and Apgar score less than five at 5 min. CONCLUSION: Late identification of hearing loss presents a substantial public health burden. Early recognition and intervention prior to 6 months of age has a significant positive impact on development. A high incidence of hearing impairment seen in our study neonatal population warrants the urgent implementation of universal hearing screening of all the newborn infants in India. NICU infants admitted for more than 24 h are to have an auditory brainstem response (AABR) included as part of their screening so that neural hearing loss will not be missed.

Relationship between leisure noise exposure and otoacoustic emissions in a young Asian population.

OBJECTIVE: This study compared the otoacoustic emissions amplitudes of Asian youths at risk of leisure noise exposure through the use of portable music players with their less exposed counterparts. DESIGN: A listening habit survey was conducted. Subjects were divided into two groups for analysis. A subject was placed within the high risk group if he/she reported listening to music at near maximum volume and had a physical measurement of his/her preferred listening level recorded at > 85 dBA. DPOAE and TEOAE levels were measured and compared between the two groups. STUDY SAMPLE: A total of 1928 students from a tertiary educational institution in Singapore. RESULTS: TEOAE levels were found to be significantly lower in the high risk group at 4 kHz. DPOAE levels were also found to be significantly depressed in the high risk group at 1, 2, 3, and 4 kHz with the largest mean difference at 4 kHz. A four-way ANOVA carried out for OAE amplitudes using gender, ear laterality, risk profile, and years of usage as independent factors also showed that risk profile was a significant factor in determining the OAE amplitude at 4 kHz. CONCLUSION: We have demonstrated that both DPAOE and TEOAE values are diminished in the Asian subjects at high risk for noise exposure.

Evaluation of distortion and transient evoked otoacoustic emission in tinnitus patients with normal hearing.

INTRODUCTION: Tinnitus is a perception of sound without external source. The exact etiology of tinnitus is not fully understood, although some researchers believe that the condition usually starts in the cochlea. The aim of this study was to determine the potential contribution of outer hair cell dysfunction to chronic tinnitus, by application of Distortion-Product Evoked Otoacoustic Emission (DPOAE) and Transient Evoked Otoacoustic Emission (TEOAE) and also to determine the relationship between tinnitus loudness and the amplitude of these two potentials. MATERIALS AND METHODS: This study was conducted on 20 tinnitus patients aged 20-45 years and 20 age- and gender-matched control subjects. DPOAE and TEOAE were performed on each subject. RESULTS: The difference in the amplitudes of TEOAE between the two groups was not significantly different (P=0.08), but the amplitude of DPOAE in patients with tinnitus was significantly lower than the corresponding value in the control subjects (P=0.01). There was no correlation between tinnitus loudness and the amplitudes of neither DPOAE nor TEOAE. CONCLUSION: Abnormal findings in the DPOAE of tinnitus sufferers suggest some form of cochlear dysfunction in these patients. As there was no correlation between the amplitude of the recorded potentials and tinnitus loudness, factors other than cochlear dysfunction may also influence the loudness of tinnitus.

The role of the medial olivocochlear system in the complaints of understanding speech in noisy environments by individuals with normal hearing.

OBJECTIVE: The aim of our study is to investigate the relationship between the complaint of speech understanding in noisy environments and the findings of contralateral suppression of transient evoked otoacoustic emissions and speech recognition in noise test methods in individuals with normal hearing. METHODS: Sixty-nine subjects between 18 and 53 years of age with normal hearing participated in the present study. The subjects were assigned to one of two groups, reported difficulty understanding speech in noise or no reported difficulty understanding speech in noise. After hearing and immitancemetric evaluation, contralateral suppression of transient evoked otoacoustic emissions and speech recognition in noise tests were administered to both groups. Suppression was calculated in half-octave frequency bands centered at 1.0, 1.5, 2.0, 3.0 and 4.0kHz. RESULTS: We found out that the speech recognition in noise scores and contralateral suppression values were lower in subjects with the complaint of speech understanding in noise than those who do not have such complaints. CONCLUSIONS: We concluded that the complaint of speech understanding in noise may be related to the medial efferent system dysfunction, so central auditory nervous system.

Effect of short duration broad band noise on transient evoked otoacoustic emission amplitude.

Transient evoked otoacoustic emission (TEOAE) is being a non-invasive, objective technique and required less time to get administered can be easily used to find out effect of short duration broad band noise (BBN). However one must know the sensitivity of TEOAEs in predicting susceptibility of noise induced hearing loss. Thus the present study has taken up to find out the effect on TEOAE amplitude because of short duration exposure of BBN. Results indicated that there was statistically significant reduction in amplitude of TEOAE at all frequencies except 1 kHz (p < 0.05). It is also observed that the basal region of cochlea is more prone to noise exposure than apical region as revealed in the outcome of the study.