Patent ID: 7039582

Claim:
A system, comprising: a first pitch estimation module to identify an initial set of pitch value candidates within each frame of a plurality of frames of received audio content utilizing a first pitch estimation algorithm, wherein identifying the initial set of pitch value candidates within each frame comprises passing each frame of audio content through an average magnitude difference function (AMDF) and selecting N near-zero minima pitch values in the audio content as the initial set of pitch value candidates; a second pitch estimation module to reduce the initial set of pitch value candidates to a select set of pitch value candidates based, at least in part, on pitch value re-scoring utilizing a second pitch estimation algorithm, wherein the select set of pitch values are selected in substantially real-time and wherein identifying a select set of pitch values comprises generating a local score for each of the initial set of pitch value candidates utilizing a normalized cross-correlation function (NCCF) and selecting M pitch value candidates with the highest local score; a transition module to calculate a transition probability between at least one of the select pitch value candidates of adjacent frames; and wherein the transition module selects a pitch value within each frame with the highest transition probability between adjacent frames as the pitch value for the frame.