Patent ID: 8121833

Claim:
A method, comprising: dividing a sound signal into a series of successive flames; dividing each frame into a number of subframes; producing, by a device, a residual signal by filtering the sound signal through a linear prediction analysis filter; locating a last pitch pulse of the sound signal of a previous frame from the residual signal; extracting a pitch pulse prototype of given length around a position of the last pitch pulse of the previous frame using the residual signal; locating pitch pulses in a current frame using the pitch pulse prototype; predicting a position of a first pitch pulse of the current frame to occur at an instant related to the position of the previously located pitch pulse and an interpolated open-loop pitch estimate at an instant corresponding to the position of the previously located pitch pulse; and refining the predicted position of said pitch pulse by maximizing a weighted correlation between the pulse prototype and the residual signal.