Speech signal detection at the output of a cochlear model

A two dimensional, linear state-space model of the cochlea of the human ear, the receiver side of the speech communications paradigm, is investigated. The ear is viewed as a serial to parallel converter of information: the input to the cochlear model is a time dependent single channel signal, whereas the output of the cochlear model is a spatially discretized representation of the displacement of the basilar membrane from its rest position. A characterization of the system response of the cochlear filters is given. An approach to detecting known signals at the input using only the information available at the output based upon methods akin to `beamforming´ for a linear array is presented. The detector threshold is set using an adaptive technique that uses spatially local information. Simulation results showing the capabilities of the detection system for processing speech signals are also discussed