[Analysis of auditory steady-state response to multiple simultaneous stimuli and cochlea morphology in guinea pigs with posterior semicircular canal fistula].

Objective: To observe the changes of auditory steady-state response (ASSR) threshold in guinea pigs with posterior semicircular canal fistula.

Methods: In 10 guinea pigs, a window was opened in the posterior semicircular canal of the left ear with the right ear serving as the control for testing the ASSR under anesthesia with pentobarbital sodium.

Results: The mean and standard deviation of ASSR threshold (dB SPL) at 0.5, 1, 2, and 4 kHz in the left ear was 35.00+/-14.33, 25.50+/-12.37, 20.00+/-9.37 and 20.00+/-9.18, respectively, and was 31.00+/-16.19, 25.50+/-12.34, 18.00+/-6.96 and 18.50+/-6.71 in the right ear, respectively. Paired-sample t test showed no significant difference in the ASSR at the same frequency between the two ears.

Conclusion: Small fistula by surgery causes no significant hearing loss in guinea pigs.