Patent ID: 9672834
Date: 2017-06-06
CPC Classifications: G10L,H04R

Claim:
1. A method of dynamic range compression with low temporal and spectral distortions for use in hearing aids and audio devices, wherein a digitized input signal is processed by sliding-band compression comprising the steps of: multiplying samples of said input signal with an analysis window to form overlapping frames; calculating short-time complex spectrum of said input signal by applying discrete Fourier transform (DFT) on said overlapping frames; calculating short-time power spectrum by summing a square of magnitude of samples of said complex spectrum lying in a band centered at each frequency sample; calculating target gain for each frequency sample using said power spectrum and a given frequency-dependent compression function; calculating a gain for each frequency sample of said complex spectrum using said target gain and selected attack and release times; multiplying each frequency sample of said complex spectrum with said gain to obtain an output complex spectrum; calculating an output segment by applying inverse discrete Fourier transform (IDFT) on said output complex spectrum; and resynthesizing an output signal by applying overlap-add on said output segment.