5. The method of claim 2 further comprising: receiving an initial plurality of frames of the speech signal; calculating the silence mean cepstral vector using the initial plurality of frames; calculating a silence cepstral distance of the initial plurality of frames using the silence mean cepstral vector; obtaining the first cepstral distance threshold and the second cepstral distance threshold using the silence cepstral distance.
6. The method of claim 5 , wherein the second cepstral distance threshold is obtained from the silence cepstral distance by multiplying by a fourth constant.