Prosodic features and the intelligibility of accelerated speech: syntactic versus periodic segmentation.

An experiment is reported in which subjects heard paragraph-length samples of time-compressed speech which were interrupted for intermediate reports either on a simple periodic basis or at points corresponding to sentence and major clause boundaries. The passages were spoken in a normal prosodic pattern, in list intonation, or were electronically processed to produce otherwise normal speech specifically deprived of pitch variation. Decrease in intelligibility scores with increasing speech rate was accompanied by a significant effect of place of interruption for report and of the prosodic pattern in which the passages were heard. Interactions among these variables were interpreted to suggest ways in which prosody ordinarily facilitates the determination of syntactic structure in connected speech.