Time-frequency analysis of TEOAE signal

TEOAEs of 30 normal hearing and 25 hearing impaired human subjects were recorded and analyzed with a PC based system designed and installed in the authors´ lab. The 3D visualized results of the time frequency analysis of TEOAE showed that the frequency components of normal hearing subjects were uniquely related to the stimulating sound and individually showed different time patterns. Moderate hearing loss at a certain frequency led to an intensity decrease at similar frequency components of TEOAE. Severe hearing losses eliminate TEOAE. Early TEOAE might be produced before 3 ms, even as early as 1 ms. This implied that the olivo-cochlear bundle was not involved in the initiation control of TEOAE. From research on the short time spectrum, time-frequency relations, and latencies of TEOAE, new approaches for revealing the mechanism of TEOAE can be reached