ISCA Archive SpeechProsody 2014
ISCA Archive SpeechProsody 2014

Effects of dynamic pitch and relative scaling on the perception of duration and prosodic grouping in American English

Alejna Brugos, Jonathan Barnes

Results of two perception experiments suggest that using timing measures alone to compute prosodic structure misses valuable information from pitch. Previous research showed that pitch can distort perceived duration: tokens with dynamic or higher f0 are perceived as longer than comparable level-f0 or lower-f0 tokens, and silent intervals bounded by tokens of widely differing pitch are heard as longer than those bounded by tokens closer in pitch (the kappa effect). Phrase edges (signalled by increased duration, pause, phrase tones, and f0 reset) set the scene for pitch to modulate perceived duration. Two new experiments used the same duration and f0 manipulations (level vs. varying-slope rises, at varying pitch ranges) of segmentally-identical base files, in two separate tasks: 1) a linguistic grouping task using an ambiguously-structured phrase and 2) a psychoacoustic study on perceived duration. Results show that effects on perceived duration due to dynamic pitch can be either strengthened or nullified depending on relative scaling of compared tokens. These same manipulations push grouping judgments beyond what would be expected from distortions of perceived duration. This suggests that listeners integrate pitch and timing cues when judging linguistic structure, supporting measures of relative boundary size that combine duration and pitch measures.