Relative contributions of formants to the intelligibility of sine-wave sentences in Mandarin Chinese.

Early sine-wave speech (SWS) studies showed that the first three formants contain sufficient intelligibility information. The present work assessed the relative perceptual contributions of the first three formants. Mandarin sentences were edited to generate two SWS conditions: removal of one of the first three formant trajectories, and preservation of only one formant trajectory. In addition, SWS synthesis was implemented in the absence of sine-wave amplitude modulation. The results consistently showed that the trajectory of the second formant contributed the most to intelligibility, and the effect of amplitude modulation was smaller than that of the formant number.