Signal processing of acoustic signals in the time domain with an active nonlinear nonlocal cochlear model

摘要

A two space dimensional active nonlinear nonlocal cochlear model isformulated in the time domain to capture nonlinear hearing effects such ascompression, multi-tone suppression and difference tones. The micromechanics ofthe basilar membrane (BM) are incorporated to model active cochlear properties.An active gain parameter is constructed in the form of a nonlinear nonlocalfunctional of BM displacement. The model is discretized with a boundaryintegral method and numerically solved using an iterative second order accuratefinite difference scheme. A block matrix structure of the discrete system isexploited to simplify the numerics with no loss of accuracy. Model responses tomultiple frequency stimuli are shown in agreement with hearing experiments. Anonlinear spectrum is computed from the model, and compared with FFT spectrumfor noisy tonal inputs. The discretized model is efficient and accurate, andcan serve as a useful auditory signal processing tool.