From tone to pitch in Sepedi

Abstract

The authors investigate the acoustic realization of tone in continuous utterances in Sepedi (a language in the Southern Bantu family). Human labelers marked each of the 271 syllables in a 15-sentence corpus produced by a single speaker as "high" or "low". Automatic pitch extraction was then used to estimate the fundamental frequencies of the voiced segments of each of these syllables. Statistical analysis of the resulting pitch contours confirms that the mean pitch frequencies of the syllabic nuclei serve as the primary indicator of tone, with the relative frequencies of successive syllables being the most relevant measure. Our analysis also suggests that additional factors may play a role in the production and perception of tone.