[Comparison of auditory brainstem responses to speech from bilateral ears with ipsilateral recordings].
OBJECTIVE
To compare the time domain and the frequency domain of speech-evoked auditory brain-stem response measured by stimulation of left and right ears, and to explore the difference and possible reasons of neural coding for speech from different ears in auditory brainstem.


METHODS
Speech-ABRs to syllable /da/ of 31 healthy adults were recorded. Statistical analysis was performed on time-domain parameters, such as latencies and amplitudes of featured peaks, and frequency-domain ones, such as amplitudes of the fundamental frequency and the first formant of speech-ABRs ranging from 20-50 ms. A scoring criterion to grade the appearance of featured waves was proposed for waveform evaluation.


RESULTS
There were no significant difference for the latencies of binaural featured peaks and amplitudes of feature peaks (except peaks A and O). The waveform .scores of right ear were greater than that of left ear. The amplitudes of fundamental frequency of binaural waves were both greater than that of the first formant. There was no significant difference of amplitudes of fundamental frequency and the first formant between two ears.


CONCLUSIONS
The origins and distributions of speech-ABR are essentially symmetrical in brainstem in contrast with the hemisphere asymmetry of speech.
Liang
Yong
Y
Department of Otolaryngology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China. yliang_2006@126.com
Fu
Qiuyang
Q
Su
Yuanyuan
Y
Wang
Tao
T
D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D004423:Ear / Q000502:physiology*; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D013060:Speech; D055815:Young Adult