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Biomedical subjects

U Ajith Kumar

Publications and source records attributed to U Ajith Kumar.

2 recordsLinked to original sources

Prevalence and audiological characteristics in individuals with auditory neuropathy/auditory dys-synchrony.

The objectives of this study were to (a) estimate the prevalence of auditory dys-synchrony in Mysore, a city of one million population in Southern India and, (b) present the results of audiological testing of this clinical population as well as the relationship between these figures. A register-based study design was employed wherein the results of audiological tests of all patients who visited the Department of Audiology, All India Institute of Speech and Hearing between January 2000 and December 2003 were reviewed. Results showed that the prevalence of auditory dys-synchrony was around 1 in 183 in individuals with sensory neural hearing loss. Behavioural thresholds and speech identification scores were variable. Around 60% of the individuals had no measurable speech identification scores. There was no relation between the hearing thresholds and speech identification scores or between otoacoustic emissions and speech identification scores. These results indicate that auditory dys-synchrony is not an extremely rare disorder.

Adolescent↗

Functioning of olivocochlear bundle and speech perception in noise.

OBJECTIVES: To evaluate the effect of contralateral acoustic stimuli on speech identification scores and to correlate this effect to contralateral suppression of evoked otoacoustic emission. DESIGN: Ten normal-hearing children with good academic performance participated in the study. Speech identification scores were measured in quiet and with different ipsilateral signal to noise ratios in two conditions, with and without contralateral acoustic stimuli. Transient evoked otoacoustic emissions were recorded for 70 dB SPL clicks with and without contralateral acoustic stimuli. RESULTS: Findings revealed that contralateral acoustic stimuli enhanced speech perception when ipsilateral signal to noise ratios was +10 dB and +15 dB. This enhancement had significant positive correlation with contralateral suppression of OAE. CONCLUSIONS: The results of the present study support the hypothesis that medial olivocochlear bundle might aid in speech perception in noise, thereby suggesting a possible role of cochlear efferent fibers in hearing. The psychoacoustic measures can be used to evaluate the efferent auditory pathways, where it is not possible to record otoacoustic emissions.

Auditory Pathways↗