Speech recognition using a cochlear model

At the 1984 IEEE ICASSP meeting Seneff described a computational model of the peripheral auditory system consisting of a bank of digital filters followed by compression and half-wave rectification stages and by a set of generalized synchrony detectors (gsd's) that respond to coherence in the signal at the center frequency of the channel. We have added adjacent-channel cross-correlation and modified the gsd. This results in improved sensitivity to formants in noise and allows human frequency masking measurements to be replicated quantitatively. When the output of the model is used in a speech recognition task it shows an advantage over a conventional filter-bank representation both with undistorted speech and in the presence of noise and linear distortion. Spectrograms generated from the model are presented both for artificially degraded speech and for speech recorded in flight in a helicopter and a fighter/trainer.