Modeling the effects of peripheral nonlinearity in listeners with normal and impaired hearing

This chapter considers the possible perceptual consequences of a reduction in peripheral nonlinearity, in particular with respect to temporal processing. It examines other tasks involving temporal processing that may be affected by changes in peripheral non-linearity. Normal-hearing listeners showed substantial excess masking in the presence of combined forward and backward maskers. In contrast, listeners with cochlear hearing impairment showed no excess masking. Changes in forward masking with level in normal-hearing listeners were successfully modeled by assuming a nonlinearity that changes with level, in qualitative agreement with basilar membrane (BM) measurements. Physiological studies of BM mechanics indicate that the response to tones presented at the characteristic frequency (CF) is nonlinear and compressive. A. J. Oxenham and B. Moore attempted to derive an appropriate weighting function for this hypothetical integrator and suggested that the model’s compressive non-linearity may reflect the compression observed on the BM in healthy cochleae in response to tones around the CF.