Burwood, George W. S. and Russell, Ian J. and Lukashkin, Andrei N. (2017) Rippling pattern of distortion product otoacoustic emissions evoked by high-frequency primaries in guinea pigs. The Journal of the Acoustical Society of America, 142 (2). pp. 855-862. ISSN 0001-4966

Burwood, George W.S. and Russell, Ian and Lukashkin, Andrei (2021) Burwood, George W. S. and Russell, Ian J. and Lukashkin, Andrei N. (2017) Rippling pattern of distortion product otoacoustic emissions evoked by high-frequency primaries in guinea pigs. The Journal of the Acoustical Society of America, 142 (2). pp. 855-862. ISSN 0001-4966. [Data Collection]

Project Description

The origin of ripples in DPOAE amplitude which appear at specific DPOAE frequencies during f1 tone sweeps using fixed high frequency f2 (>20kHz) in guinea pigs is investigated. The peaks of the ripples, or local DPOAE amplitude maxima, are separated by approximately half octave intervals and are accompanied by phase oscillations. The local maxima appear at the same frequencies in DPOAEs of different order and velocity responses of the stapes and do not shift with increasing levels of the primaries. A suppressor tone had little effect on the frequencies of the maxima, but partially suppressed DPOAE amplitude when it was placed close to the f2 frequencies. These findings agree with earlier observations that the maxima occur at the same DPOAE frequencies, which are independent of the f2 and the primary ratio, and thus are likely to be associated with DPOAE propagation mechanisms. Furthermore, the separation of the local maxima by approximately half an octave may suggest that they are due to interference of the travelling waves along the basilar membrane at the frequency of the DPOAE. It is suggested that the rippling pattern appears because of interaction between DPOAE reverse travelling waves with standing waves formed in the cochlea.