Patent ID: 8447601
Filing Date: 2013-05-21
Classification: G10L

Abstract:
1. A method for tracking background noise in a communication system, comprising: calculating a Signal to Noise Ratio (SNR) of a current frame according to input audio signals; increasing a frame counter cnt determining the possibility of a time window comprising a noise interval according to the tone feature value and the signal steadiness feature values of each frame of the time window when the frame counter cnt extracting noise features in the time window according to the determined possibility of the time window comprising a noise interval, wherein calculating values for tone features and signal steadiness features of the current frame comprises: calculating the tone feature values of the current frame, a spectrum fluctuation value spdev of the current frame, a spectrum peak position fluctuation value of the current frame, and a spectrum maximum Peak to Valley Ratio (PVR) position fluctuation value of the current frame, wherein calculating the tone feature value of the current frame comprises: calculating a sum of the largest three normalized PVRs of the spectrum according to a formula of tonal=PVR wherein calculating the spectrum fluctuation value spdev of the current frame comprises: calculating the spectrum fluctuation value spdev according to the formula of  where M is an average value of E wherein calculating the spectrum peak position fluctuation value P wherein calculating the spectrum maximum PVR position fluctuation value Mp wherein idx