A sawtooth waveform inspired pitch estimator for speech and music

Abstract

A sawtooth waveform inspired pitch estimator (SWIPE) has been developed for speech and music. SWIPE estimates the pitch as the fundamental frequency of the sawtooth waveform whose spectrum best matches the spectrum of the input signal. The comparison of the spectra is done by computing a normalized inner product between the spectrum of the signal and a modified cosine. The size of the analysis window is chosen appropriately to make the width of the main lobes of the spectrum match the width of the positive lobes of the cosine. SWIPE′, a variation of SWIPE, utilizes only the first and prime harmonics of the signal, which significantly reduces subharmonic errors commonly found in other pitch estimation algorithms. The authors’ tests indicate that SWIPE and SWIPE′ performed better on two spoken speech and one disordered voice database and one musical instrument database consisting of single notes performed at a variety of pitches.