Auditory Brainstem Response in Children with Thalassemia Major under Chelating Therapy.

The present study compared the Auditory Brainstem Response (ABR) of children with thalassemia major and typically developing children. A total of 16 children participated in this study. Group I included 8 children with thalassemia major regularly undergoing blood transfusions and chelating therapy. Group II included 8 age and gender-matched typically developing children. All children in both groups had hearing sensitivity within normal limits. The Auditory Brainstem Response (ABR) was recorded monaurally for click stimuli from both ears. Results showed that the mean latencies of peaks of ABR were similar in both groups. The mean peak amplitude of peaks I and V of the ABR were different between groups, but it was not statistically significant. The present study showed no abnormality in the latency and amplitude of peaks of the ABR in children with thalassemia major with hearing sensitivity within normal limits.

The effect of coffee on contralateral suppression of transient evoked otoacoustic emissions.

Background: Coffee is a popular non-alcoholic beverage consumed by humans across the world. It contains caffeine, which is a type of stimulant of the central nervous system. In the auditory system, it has a positive effect on auditory brainstem response and perception of speech in noise. Further, caffeine has an inhibitory effect in the cochlea, but studies have rarely investigated its effect on otoacoustic emissions (OAEs) in humans. OAEs are low-intensity sounds produced by the cochlea, which could be recorded in the ear canal. The present study was carried out to investigate the effect of coffee on transient evoked otoacoustic emission (TEOAE) and contralateral suppression of TEOAE. Method: A total of 52 young adults participated in the study. A cross-over study design was used for the present investigation. The TEOAE and contralateral suppression of TEOAE were recorded before and after consumption of coffee and milk. The contralateral suppression of TEOAE was measured by presenting white noise to the contralateral ear at 40, 50, and 60 dB sound pressure level (SPL). Results: The mean amplitude of TEOAE before and after consumption of coffee was similar in both ears. Further, the mean contralateral suppression of TEOAE was slightly larger after consumption of coffee in both ears. However, the mean difference was not significant in both the ears. Conclusions: Based on the findings of present study, coffee has no significant effect on the amplitude of TEOAE and contralateral suppression of TEOAE.

Effect of pre-transition stimulus duration on acoustic change complex.

OBJECTIVE: To investigate the effect of pre-transition duration on acoustic change complex (ACC) for speech and tonal stimulus. DESIGN: Cortical potentials were recorded for consonant-vowel syllable and tonal complex stimuli with varying pre-transition durations. STUDY SAMPLE: Ten individuals (three male and seven female) in the age range from 18 to 26 years, with normal hearing sensitivity, participated in the study. RESULTS: The results revealed that a minimum pre-transition duration of 100 ms for tonal stimulus (with spectral change) and 80 ms for consonant-vowel syllable is necessary in order to elicit ACC. The latency of N1(1) and P2(1), which is the response for change within the ongoing stimulus, increased with increase in pre-transition duration. The amplitude of the evoked responses did not show any significant change. CONCLUSIONS: It was found that minimum pre-transition duration required in eliciting ACC for speech and non-speech stimulus is not same. The speech stimulus required lesser duration of pre-transition than non-speech stimulus. Further studies regarding the acoustic aspects of sound on CAEP in isolation are warranted.