Patent ID: 8725498

Claim:
A computer-implemented method comprising: receiving, by one or more servers, digital speech data from a computing device; determining, by the one or more servers, a respective pitch of the digital speech data for each of multiple time segments; determining, by the one or more servers and for each of the multiple time segments, a logarithm of the pitch of the digital speech data for the time segment; after determining the respective logarithm of the pitch of the digital speech data for each of the multiple time segments, determining whether each time segment is classified as a voiced time segment or as an unvoiced time segment; for each time segment that is classified as a voiced time segment, determining a first order derivative of the logarithm of the pitch for the time segment; for each segment that is classified as an unvoiced time segment, obtaining zero-mean random noise; and combining (i) the first order derivative of the logarithm of the pitch, for each time segment that is classified as a voiced time segment, with (ii) the zero-mean random noise, for each time segment that is classified as an unvoiced time segment.