NONLINEAR SIGNAL PROCESSING IN A SPEECH RECOGNITION SYSTEM An acoustic processor and a method of processing an acoustic wave input which includes a non-linear auditory model of the neural firing rate in the ear. The firing rate is determined by the replenishment of neurotransmitter and loss of neurotransmitter due to spontaneous decay, spontaneous firing, and acoustic wave inputs defined, preferably, in sones. The number of free parameters in the acoustic processor is reducible to one, namely the ratio R of two steady-state firing rates each resulting from a different loudness. Preferably, the free parameter is adjusted to minimize steady-state effects which are adversely impacted by speaker differences, background noise, distortion, and the like. The present invention addresses the general problem of processing an acoustic wave input in a speech recognition system and addresses the specific problem of adjusting acoustic processor performance to reduce adverse effects.
NONLINEAR SIGNAL PROCESSING IN A SPEECH RECOGNITION SYSTEM