Abstract:

Objective      To compare the difference of the threshold of normal guinea pigs between auditory brainstem response (ABR) and auditory steady state response (ASSR), and provide a theoretical basis for hearing research on guinea pigs.  Methods      12 guinea pigs (24 ears) with normal hearing sedated by pentobarbital sodium were selected for the ABR and ASSR tests. The click- ABR stimulation rate was 11.1 beats/s, and the Ⅱwave thresholds were recorded as the ABR response threshold. The carrier frequencies(CF) of ASSR were 0.5,1,2,3,4 and 6kHz, the modulation frequency (MF) was 154Hz, and the threshold of each carrier frequency was recorded.  Results       The threshold of ASSR was higher than that of ABR at 0.5-4kHz CF in normal guinea pigs(P<0.01), but no significant difference was found at 6kHz CF（P＞0.05）.  Conclusion      There are significant differences in most thresholds of ASSR and ABR in normal guinea pigs. However, there is no significant difference at 6kHz CF. Therefore, the differences caused by different CF of ASSR must be noted when assessing the hearing of guinea pigs.

Key words: Auditory brainstem response； Auditory steady state responses； Guinea pigs