Final Report on Contract Number N00014-86-C-0051 (ONR).
Abstract
Research has been directed towards discovering novel nonlinear signal processing principles by studying the way in which the inner ear analyzes sound and encodes the information contained therein as neural impulses. These principles may be abstracted from the context of hearing and usefully applied to the analysis of any type of nonstationary signal containing both time and frequency information. Applications of this work to the recognition of speech in noisy environments and the classification of ocean sounds are expected. The central research problem has been the characterization of the nonlinear mechanics of the inner ear and the elucidation of its role in signal processing. The mechanics of the inner ear at low sound pressure levels (levels of unvoiced speech) has been accurately characterized with the unexpected conclusion that the inner ear functions as an active nonlinear one-dimensional mechanical transmission line with negative feedback involving delay. The parameters defining the circuit elements vary gradually along the line. Each section of the line contains a negatively damped harmonic oscillator stabilized by the feedback of a force proportional to the displacement of the oscillator at a time in the past, where the time delay of the force is proportional to the oscillator's period. Keywords: Cybernetics; Acoustic detectors; Acoustic data; Acoustic signals.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 1987
- Accession Number
- ADA191644
Entities
People
- George Zweig