Patent Document ID: 8010350
Application ID: 11734824
Patent Status: 1

Claim One:
1. A method for refining an estimated pitch period associated with an audio signal, comprising: (a) setting an initial coarse pitch lag (P 0 ) associated with the audio signal as a best pitch lag; (b) setting a normalized correlation associated with the initial coarse pitch lag as a best normalized correlation; (c) calculating a refinement pitch range based on an ideal pitch and the initial coarse pitch lag; (d) calculating a normalized correlation at a first midpoint of the refinement pitch range preceding the best pitch lag and at a second midpoint of the refinement pitch range following the best pitch lag; (e) comparing the normalized correlation at each of the first and second midpoints to the best normalized correlation; and (f) responsive to a determination that the normalized correlation at either of the first and second midpoints is greater than the best normalized correlation, setting the greatest normalized correlation associated with each of the first and second midpoints to the best normalized correlation and setting the midpoint associated with the greatest normalized correlation to the best pitch lag.