F0 perturbations by consonants and their implications on tone recognition

In this paper, we present a study on variations of fundamental frequency (F₀) in speech production of Mandarin Chinese, and discuss the implications of our results for automatic tone recognition. Target syllables with different consonants and tones were analyzed in continuous speech samples. Compared to the control syllable /ma/ which shows a smooth transition from the onset F₀ value to the current tonal target, syllables with voiceless initial consonants have local raisings of F₀ at voice onset and shorter F₀ trajectories. The effect known as consonant perturbation on F₀ is local and does not alter the original course of known contextual tonal variations. Rather, it is superimposed on other effects, and thus contributes to the appearance of surface F₀ contours. Understanding and consideration of consonant perturbation on F₀ curves therefore should help improve the performance of current tone recognition systems.