Parameters of Speech Rate Perception in German Words and Sentences: Duration, F o Movement, and F o Level

Through four sets of experiments, this paper examines the contributions of duration, overall F o level and F o movement to the perception of speech rate in German words and sentences, as well as the influences of perceived tempo changes on segment identity. Overall duration constitutes the most important cue, and overall F o level is stronger than F o movement. A higher F o level cues a faster, a lower F o level a slower speed, in relation to some medium reference. An F o movement below or above a preceding Fo level signals a decrease or an increase in speech rate, respectively. Gliding changes have greater cue strength than stepwise changes, and early glides in stressed-unstressed syllable sequences are stronger than later ones. Segment perception that relies on local duration ratios takes their tempo-induced changes into account: The identification functions shift to higher ratios for slower speech rates and to lower ratios for faster speech rates. These perceptual findings are closely linked with the timing and Fo control in speech production.