A subjective evaluation of pitch detection methods using LPC synthesized speech

A subjective evaluation of seven pitch detectors has been carried out using synthetic speech. The evaluation is intended to complement the objective performance evaluation of the same pitch detection algorithms in the investigation of Rabiner et al. [1]. In the earlier study, each of the seven algorithms was evaluated on the basis of its performance with respect to four different types of errors. The standard of comparison was a semiautomatically determined pitch contour of each utterance in the experimental corpus. In the present study, the quality of LPC (linear predictive coding) analyzed and synthesized speech was evaluated. The pitch contour used in the synthesis was obtained either from one of the seven pitch detectors or from the semiautomatic pitch analysis. Using a computer-controlled sort board, an experiment was run in which each of eight listeners was asked to rank the nine versions of each utterance (the natural version was included to provide a stable anchor point). Results are presented on the overall preference for each pitch detector. In addition, subject preference as a function of the pitch range of the speaker and the transmission environment used in the recording is discussed. The present results are compared to those obtained in the earlier objective performance study.