A 360-Channel Speech Preprocessor that Emulates the Cochlear Amplifier

Abstract

A cochlea-based preprocessor for speech recognition emulates the fluid ducts with two 4680-element diffusive grids, the basilar membrane with 360 2nd-order sections, and the auditory nerve with 2160 pulse-frequency modulators. Integrated in 10.9mm2in 0.25mum CMOS and consuming 52mW, this silicon cochlea employs active bidirectional coupling, a selective amplification mechanism that sharpens tuning (Q10 is 2.7) and controls gain (24dB compression)