VOICED-SPEECH REPRESENTATION BY AN ANALOG SILICON MODEL OF THE AUDITORY PERIPHERY

This paper presents an analog CMOS integration of a model for the auditory periphery. The model consists of middle ear, basilar membrane, and hair cell/synapse modules which are derived from neurophysiological studies. The circuit realization of each module is discussed and we show experimental data of their response to sinusoidal excitation. The nonlinear speech processing capabilities of the system are demonstrated using the voiced syllable/ba/. The multichannel output of the silicon model corresponds to the time-varying instantaneous firing rates of auditory nerve fibers that have different characteristic frequencies. These outputs are similar to the physiologically obtained responses. The actual implementation employs subthreshold CMOS technology and analog continuous-time circuits, resulting in a real-time, micropower device with potential applications as a preprocessor of auditory stimuli.