Patent ID: 8213636
Filing Date: 2012-07-03
Classification: G10L,H04R

Abstract:
1. A method of reconstituting low frequencies of an audio signal output by a sound playback device ( 11 , 12 ) having a low cutoff frequency (F 0 ), the method comprising the steps of: filtering the audio signal by means of a lowpass filter ( determining a fundamental frequency to be reconstituted from the lowpass filtered audio signal; and generating a harmonic signal (S the method being characterized by the steps of: detecting a time envelope (env(t)) of the lowpass filtered audio signal; adapting the dynamic range of said time envelope (env(t)) as a function of the frequency band under consideration, wherein adapting is performed by compression/expansion ( reinjecting said harmonic signal in phase into said audio signal by addition, after multiplying said harmonic signal (S