An analytical lumped-parameter 3D cochlear model and architecture for cochlear signal processing in VLSI

Design considerations for a neuromorphic cochlear implant and its system architecture are given. A set of equations describing a fully continuous complete (3-turn) analytical 3D lumped-parameter (LP) impedance model based on in-vivo guinea-pig cochleae measurements and qualitative reasoning is introduced. 3D phase and amplitude in the organ of corti (OC) can be visualised from a stimulus presented at the round window (RW) for normal and implanted cochleae. A SPICE model uses nonlinear longitudinal resistors and linear (transversal) Rs and Cs which can be easily made amplitude and/or freq. dependent. The methodology is used in devising a new non-linear, multi-functional cochlear architecture to aid the synthesis of circuit building blocks representing sensory transduction. Further model applications include realistic and computationally efficient studies of electrode stimulation issues in implanted cochleae, and frequency-domain mapping of compressive and expansive OC nonlinearities for future silicon VLSI closed-loop cochlear implants or speech recognition