INTERPITCH · Interdisciplinary investigation of Pitch coding in whispered speech

The goal of the InterPitch project is to systematically investigate how intonation (speech melody) is coded in whispered speech. A speaker who whispers fails to produce the most important cue to intonation perception, i.e. the fundamental frequency (F0). Assuming that the speaker attempts to accommodate the listener during communication, the whispering speaker is expected to naturally compensate for the loss of that cue by exploiting (and exaggerating) alternative acoustic cues to pitch. The project will investigate both the presence and nature of cues to intonation in whispered speech, and their relevance for listeners. The project will take an interdisciplinary approach by combining acoustic-phonetics, “the production perspective”, and psychoacoustics, “the perception perspective”. This captures the full speech chain, i.e. the model of how a message is transferred from the mind of the speaker to the mind of the listener. The test case will be Clause Typing, i.e. signaling whether a sentence is a question or a statement through intonation. This phenomenon is found in many European languages in similar ways. Through extensive psychoacoustic and phonetic analyses of whispered and phonated speech the contents of the speech signal in both questions and statements will be investigated. Through perception tests the specific contribution of temporal coding to intonation perception will be studied, and the availability of acoustic cues to hearing impaired listeners will be simulated. The results contribute to understanding the fundamental relation between mental representations of language and their realisations in both regularly phonated and whispered speech. The results may furthermore be used for synthesis of whispered speech, which has applications in text-to-speech systems, and for new ways of coding pitch information in cochlear implant processors for hearing impaired populations.