Difference limens for fundamental frequency contours in sentences

Difference limens (DLs) for fundamental frequency (F0) of naturally spoken sentences were studied. The experiments can be classified into two major categories. In the first category the fundamental frequency of a portion of sentences of 2 to 3 s in duration was manipulated. The second set of experiments used very short sentences (‘‘The subject verb’’) in which the F0 of the entire sentence was manipulated. Across experiments, sentences of comparable length yielded similar DLs, except when the F0 was abruptly shifted within a continuous voicing period. However, the DLs did vary significantly as a function of stimulus complexity and speaker. The range of DLs obtained in this series of experiments was between 10 and 50 times greater than that found with sustained synthetic vowels.