[Auditory brainstem responses by click stimuli via an earphone--comparison with a headphone]

To evaluate the variations of auditory brainstem responses (ABR) recorded using different receivers, the recordings of ABR were performed in 10 neurologically and audiometrically normal subjects who were all females (20-21 years of age) using a headphone (DR-513B-6) and an earphone (YE-102J). The peak latencies, the interpeak latencies, and the amplitudes of wave I, III, and V at each ABRs were compared. Unilateral auditory stimuli consisted of alternate click with 0.1 msec duration at intensity of 110 dB SPL and at rate of 13 Hz was given to the subjects who lay in the supine position at awake state. The active electrode was placed on the vertex (Cz) and the reference electrode on the left or right mastoid. The responses recorded from Cz to the ipsilateral mastoid were amplified by a factor of 10 microV/DIV with a bandpass filter of 10 Hz-3 KHz, a total of 1000 responses was averaged. It was recognized that the output intensity via the earphone was lower than the headphone, the difference was approximately 5 dB. Furthermore, the frequency response of the earphone was worse than the headphone at high frequency area (over 3.5 KHz). There were characteristic differences between ABRs recorded using the headphone and the earphone. The prolongation of the latency and the decrease of the amplitude were identified at only wave I of ABRs recorded using the earphone. However, no significant changes were founded at another components.(ABSTRACT TRUNCATED AT 250 WORDS)