Patent ID: 8194725

Claim:
A method for reducing ringing in a speech signal comprising: inputting the speech signal into a filter; filtering a first portion of the input speech signal to generate a filtered portion of an output signal; analyzing the filtered portion of the output signal by: determining the energy of a frame of the input speech signal; and determining the energy of a frame of the filtered portion of the output signal; detecting if ringing is present in the filtered portion of the output signal based on said analysis by: comparing the energy of the frame of the filtered portion of the output signal to the energy of the frame of the input speech signal; and determining that ringing is present on the output signal if the energy of the frame of the filtered portion of the output signal is greater than the energy of the frame of the input signal; adjusting the filter characteristics to reduce ringing in a subsequent filtered portion of the output signal by outputting a control signal to the filter if it is determined that ringing is present in the filtered portion, where the control signal that is output to the filter dampens the response time of the filter; filtering a subsequent portion of the speech signal to generate the subsequent filtered portion; and encoding the speech signal after filtering the subsequent portion.