Computational techniques for continuous pitch correction and harmony generation

Abstract

Using signal processing techniques described herein, pitch detection and correction of a user's vocal performance can be performed continuously and in real-time with respect to the audible rendering of the backing track at the handheld or portable computing device. In some implementations, pitch detection builds on time-domain pitch correction techniques that employ average magnitude difference function (AMDF) or autocorrelation-based techniques together with zero-crossing and/or peak picking techniques to identify differences between pitch of a captured vocal signal and score-coded target pitches. Based on detected differences, pitch correction based on pitch synchronous overlapped add (PSOLA) and/or linear predictive coding (LPC) techniques allow captured vocals to be pitch shifted in real-time to 'correct' notes in accord with pitch correction settings that code score-coded melody targets and harmonies.