Abstract: Intracellular recordings were made from outer hair cells (OHC) and the cochlear microphonics (CM) were recorded from scala media (SM) in third turn of guinea pig cochlea,the compound action potential (CAP) were recorded at the round window (RW) before and after the animal were exposed to white noise.The results suggest that the nonlinear properties with'saduration'of Input/output (I/O) function of OHC AC recepter potential and CM were founded;the nonlinear properties with'Low','Platean'and'high'of CAP also were investigated.After explosion,the threshold shift of CAP has about 10 dB.The I/O of OHC responses and CM were changed in a linearizing (i.e.,nonlinearity loss),the'platean'of I/O CAP disappeared and the growth rate of CAP amplitude were larger than before explosion.The response amplitude recruitment of OHC appears to result from reduction in gain (i.e.,hearing loss);It was due to the nonlinear growth function of OHC recepter potentials was changed in linearizing that the basilar membrance motion was changed in linearizing.Since intensity coding in the inner ear dependson an interaction of nonlinear basilar membrane and nerve fibers.So that it must lead to a linearizing of CAP as input responses.