Abstract: The Corti's organs of the guinea pigs were examined by scanning electron microscope either immediately or 1,3,7,15,or 30 days after the exposure to continuous white noise at different intensities of 125 dB SPL and 132 dB SPL for 1 hour.Swelling,fusion,collapse and even loss of OHC stereocilia were mainly observed in the third and forth turns of cochlea. There was a lesion length of 10mm of corti's organ in guinea pigs immediately after the exposure to white noise at 132 dB SPL,and 7 mm at 125 dB SPL.70% of OHC was damaged in the lesion length of 10 mm of Corti's Organ in guinea pigs immediately after the exposure to white noise at 132 dB SPL,and 50% of OHC in the lesion length of 7 mm at 125dB SPL.The lesion length of Corti's organ and the amount of OHC were increased with the intensity of white noise,and decreased with the survival intervals after the exposure.The slight damage to OHC stereocilia,such as swelling and fusion,could be recoverable subsequent to the exposure to white noise,but the moderate and severe damage,such as collapse and loss of stereocilia were unrecoverable.It seemed that the early stage(less than 15 days after the exposure to white noise at 132 dB SPL,and 7 days at 125 dB SPL)was essential for the affected OHCto recover from the damage.The relationship of the features of damage to hair cells with white noise was discussed.

Key words: white noise, Corti's organ, scanning electron microscope