SYSTEMS TECHNOLOGIES FOR SILICON AUDITORY MODELS

Our low-power analog integrated circuit implements a biologically insp ired algorithm for the spectral analysis of sound. The chip features a n efficient interface to digital systems; preserving analog processing 's low-power, high-density advantages requires careful attention to in terface issues. To send the spectral representation off chip, we gener ate a sparse coding of the output spectrum, and communicate the code a s an asynchronous stream of events. We store parameters for the spectr al analysis algorithm as charge on floating nodes, and support the mod ification of these parameters via Fowler-Nordheim tunneling, under the control of a digital interface. A prototype system we have developed uses this chip as a preprocessor.