Patent ID: 7752037

Claim:
A method of determining a pitch period of an audio signal based on a correlation-based signal derived from the audio signal, the correlation-based signal including known local peaks each corresponding to a respective known time lag, the local peaks including a known global maximum local peak, each local peak corresponding to a known interpolated peak, comprising: (a) receiving, from a signal processor, a candidate local peak (CLP) indicator having either (i) a first indicator value indicating that a CLP exists among the local peaks, the CLP corresponding to a time lag within a predetermined range of a previously determined pitch period of the audio signal, and an interpolated peak exceeding a first peak threshold, or (ii) a second indicator value indicating that no CLP exists among the local peaks; (b) if the second indicator value is received, then setting the pitch period equal to the time lag corresponding to the global maximum local peak; and (c) if the first indicator value is received, and if the CLP is the same as the global maximum local peak, then setting the pitch period equal to the time lag corresponding to the global maximum local peak.