In the audio watermarking extraction,how to extract the watermark information from the embedded watermarking audio which has been disturbed or attacked,or proves the existence of the watermark information is the key and difficult point.This paper firstly gave a brief description about the audio watermark extraction algorithm,aiming at the effects of the audio signal variance on watermark extraction results.Then it implemented four methods of reducing the audio signal variance and analysed the experiment results in MATLAB.Based on the implementations and filtering results of the four methods,th...