Prosody production in spontaneous speech: Phonological encoding, phonetic variability, and the prosodic signature of individual speakers.

Abstract

We examine the prosodic variation in production with corpus and experimental speech materials. Prosodic transcription of spontaneous speech from the Buckeye corpus of American English (38 speakers, 54 excerpts, 11–55‐s duration each) reveals striking inter‐speaker variation in the frequency and distribution of prosodic prominences and boundaries, and in acoustic correlates (pitch, intensity, duration, and spectral measures). Inter‐transcriber agreement rates also vary systematically across speakers, suggesting inter‐speaker differences in the clarity/consistency of prosodic cues. To further explore variability in the phonological and phonetic expression of prosody while holding lexico‐syntactic content constant across speakers, we conducted an auditory repetition experiment. Ten American English speakers listened to 32 excerpts (8–15 words each, 4 speakers) from the American English Map Task corpus and reproduced each utterance with the exact words and “in the way the speaker said them”, without text prompts. Preliminary results from prosodic transcription and acoustic analysis show reliable replication of the phonological structures locating prosodic prominences and phrase boundaries, but with variation in the pitch melody and other phonetic details of the prosodic features. These findings shed light on the mapping between the phonological encoding and the acoustic expression of prosodic features, and highlight those acoustic parameters that identify the prosodic signature of individual speakers.