Patent ID: 8526650
Filing Date: 2013-09-03
Classification: H04R

Abstract:
1. A method for processing an audio signal received by a hearing assistance device, comprising: filtering the audio signal to generate a high frequency filtered signal, the filtering performed at a splitting frequency; transposing at least a portion of an audio spectrum of the filtered signal to a lower frequency range by a transposition process to produce a transposed audio signal; and summing the transposed audio signal with the audio signal to generate an output signal, wherein the transposition process includes: estimating an all-pole spectral envelope of the filtered signal from a plurality of line spectral frequencies; using a digital signal processor, applying a warping function to the all-pole spectral envelope of the filtered signal to translate the poles above a specified knee frequency to lower frequencies, thereby producing a warped spectral envelope; and exciting the warped spectral envelope with an excitation signal to synthesize the transposed audio signal.