"Syncpitch": A pseudo pitch synchronous algorithm for speaker recognition

Abstract

Pitch mismatch between enrollment and testing is a common problem in speaker recognition systems. It is well known that the fine spectral structure related to fundamental frequency manifests itself in Mel cepstral features used for speaker recognition. Therefore pitch variations result in variation of the acoustic features, and potentially an increase in error rate. A previous study introduced a signal processing procedure termed depitch that attempts to remove pitch information from the speech signal by forcing every speech frame to be pitch synchronous and include a single pitch cycle. This paper presents a modification of the depitch algorithm, termed syncpitch, that performs pseudo pitch synchronous processing while still preserving the pitch information. The new algorithm has a relatively moderate effect on the speech signal. System combination of syncpitch with a baseline system is shown to improve speaker verification accuracy in experiments conducted on the 2002 NIST Speaker Recognition Evaluation data.