On the shape of (evoked) otoacoustic emission spectra

In a preceding paper [Wit et al., (1994) Hear. Res. 73, 141-147] it was shown that realistic time-frequency plots for click evoked otoacoustic emissions can be synthesized by adding a large number of gammatones. It is necessary in such a synthesis to make the inner ear frequency to place map, from which the central frequencies of the gammatones are taken, slightly irregular along the entire cochlear partition. The present paper shows that this approach leads, in a rather straightforward way, to (quasi-) periodicity in synthesized spectra of evoked otoacoustic emissions. These spectra show good resemblance with spectra from real ear emission measurements.