AIM To explore the effects of infrasound on auditory threshold and morphology of cochlear hair cells in guinea pigs. METHODS The guinea pigs were exposed to infrasound with 8 Hz, 125 dB SPL, 2 h/time, 1 time/d for 30 days. and the changes of auditory threshold and morphology of cochlear hair cells were observed by auditory brainstem response audiometry (ABR) and scanning electron microscopy (SEM). RESULTS The increase of ABR auditory threshold could be seen in all nine frequencies of toneburst and click ...