Cochlear Fine Structure—Implications for Modulation Processing at the Level of the Cochlea

It was proposed that fine structure effects in OAEs or threshold in quiet are a consequence of the active and nonlinear processing at the level of the cochlea. For human listeners it was shown that fine structure affects the detection of sinusoidally amplitude modulated tones (SAM) with low carrier levels [Heise et al. 2009 J Acoust Soc Am 126:2490–2500].

The present study uses a one dimensional nonlinear and active transmission line model of the cochlea to simulate modulation perception and to study the explanations for the psychoacoustical effects given in the literature. The model was already successfully applied to simulate the fine structure of the threshold in quiet including SOAE in fine structure minima.

It is investigated to which extent the representation of the modulated stimulus at the level of the cochlea can be used to identify the mechanism underlying differences found in data and to which extent it can be used to account for psychophysical data near threshold.