Patent ID: 6980665

Claim:
A method of processing sound in a hearing aid, comprising the steps of: receiving acoustical signals within the hearing aid; transforming the acoustical signals into digital input signals; passing a portion of said digital input signals through a plurality of cascaded all-pass filters to form a sequence of delayed samples; windowing said sequence of delayed samples; applying a frequency domain transform to said windowed sequence of delayed samples to form a warped sequence; calculating a plurality of frequency domain level estimates from said warped sequence; calculating a plurality of frequency domain gain coefficients from said plurality of frequency domain level estimates to form a warped time-domain filter; calculating a plurality of spectral enhancement gain coefficients from said warped sequence; calculating a plurality of compression-spectral enhancement gain coefficients from said plurality of frequency domain gain coefficients and said plurality of spectral enhancement gain coefficients; applying an inverse frequency domain transform on said plurality of compression-spectral enhancement gain coefficients to form a set of time-domain filter coefficients; and convolving said sequence of delayed samples with said set of time-domain filter coefficients to produce a digital output signal.