SPEECH CODING METHOD APPLYING NOISE REDUCTION BY MODIFYING THE CODEBOOK GAIN

摘要

The invention refers to a method for encoding an acoustic signal (y(n)) containing a speech component and a noise component by using an analysis through synthesis method, wherein for encoding the acoustic signal a synthesised signal is compared with the acoustic signal for a time interval, said synthesised signal being described by using a fixed codebook and an associated fixed gain, comprising the steps: Determining a fixed gain (gy(m)) of the acoustic signal (y(n)) for the time interval; Extracting an estimated fixed gain (gn) of the noise component from the acoustic signal (y(n)) for the time is interval; Deriving an estimate of the fixed gain (gSj(m)) of the speech component by subtracting said fixed gain of the noise component from the fixed gain (gy(m)) of the acoustic signal for the time interval.