Perception of prominence in speech intonation induced by rising and falling pitch movements

The object of this study was to investigate whether subjects are able to compare the prominence caused by different types of accent-lending pitch movements and, if so, whether some pitch movements lend more prominence to a syllable than others. These experiments were carried out with the utterance /ma’mama/, with the second syllable accented by either a rise, a fall, or a rise–fall. Subjects adjusted the variable excursion size of a comparison stimulus to the fixed excursion size of a test stimulus in such a way that the accented syllable in test and comparison stimuli had equal prominence. The rise–fall was only presented in one ‘‘standard’’ position, while the fall and the rise were tested for five different temporal positions in the syllable. Subjects were found to be quite capable of equating the prominence of syllables accented by the following types of pitch movement: the rise–fall in standard position, the rise starting before the vowel onset, and the fall whatever its temporal position in the syllable. When lending equal prominence, the early starting rise and the rise–fall had equal excursion sizes. The fall, however, appeared to lend more prominence to a syllable than the rise or the rise–fall of equal excursion size, independent of its position in the syllable. This difference between the fall on the one hand and the rise and the rise–fall on the other increased with increasing declination of the pitch contour. A model is presented which can explain these phenomena quantitatively.