Two-tone distortion products in a nonlinear model of the basilar membrane.

Two‐tone distortion products were studied in a computational model of the basilar membrane into which second‐ and third‐order nonlinearities had been introduced. The displacement patterns produced by distortion products f2 − f1 and 2f1 − f2 resemble, in the neighborhood of the characteristic place for the frequency in question, displacement patterns produced by tones delivered at the stapes. This is not the case for distortion product 2f2 − f1. The dependence of both the amplitude and phase of distortion products f2 − f1 and 2f1 − f2 on frequency spacing and amplitude of the two primary tones has features in common with results from psychophysical experiments. The 2f1 − f2 distortion product shows a nonmonotonic behavior similar to that demonstrated in psychophysical experiments. The phase of the 2f1 − f2 distortion product changes with intensity in a manner similar to that observed psychophysically. In the model, a cancellation‐tone method overestimates the amplitude of the 2f1 − f2 distortion product, a...