Binaural source localizer chip using subthreshold analog CMOS

This article describes a chip that identifies the azimuthal location of a sound source using the arrival time difference at two separated microphones. Its circuits are modeled on certain aspects of auditory neurobiology, and attempt to base the location precept on the arrival time difference of the first wavefront in order to function in echoic environments as well as free field situations, The chip contains approximately 50000 transistors, mostly operating in the subthreshold analog mode. It was fabricated on a 4.6 mm×6.8 mm die a standard 2-micron, p-well CMOS process through MOSIS