ABSTRACT
The spontaneous otoacoustic emissions(SOAEs) and spontaneous cochlear microphone potential (SCM) were observed in 8 guinea pigs from 168 normal guinea pigs. Second and third harmonics of SOAE had been observed in three animals. The distortion product otoacoustic emissions(2f1-f2) were created with an external tone as f2 and the SOAE as f 1 in 6 animals , SOAE were suppressed by contralateral broadband noise stimulation and enhanced by strychnine . The suppression tuning curve was similar to the two tone suppression. The results indicate that SOAE and SCM are spontaneous electromotile vibration of outer hair cells. The model of spontaneous vibration and characteristic of audiology is the same as that of hearing of external tone and it can be modulated by efferent system.