Xing Fu Li

US Patent:

8019431, Sep 13, 2011

Filed:

Jun 2, 2009

Appl. No.:

12/476979

Inventors:

Kaibao Nie - Bothell WA, US
Les Atlas - Seattle WA, US
Jay Rubinstein - Seattle WA, US
Xing Li - Bellevue WA, US
Charles Pascal Clark - Seattle WA, US

Assignee:

University of Washington - Seattle WA

International Classification:

A61N 1/00

US Classification:

607 57

Abstract:

The restoration of melody perception is a key remaining challenge in cochlear implants. A novel sound coding strategy is proposed that converts an input audio signal into time-varying electrically stimulating pulse trains. A sound is first split into several frequency sub-bands with a fixed filter bank or a dynamic filter bank tracking harmonics in sounds. Each sub-band signal is coherently downward shifted to a low-frequency base band. These resulting coherent envelope signals have Hermitian symmetric frequency spectrums and are thus real-valued. A peak detector or high-rate sampler of half-wave rectified coherent envelope signals in each sub-band further converts the coherent envelopes into rate-varying, interleaved pulse trains. Acoustic simulations of cochlear implants using this new technique with normal hearing listeners, showed significant improvement in melody recognition over the most common conventional stimulation approach used in cochlear implants.