Acoustic cues to prominence and phrasing in bilingual speech

Abstract

This dissertation investigates the prosodic structure of French and the Oceanic language Drehu, spoken by a small bilingual community on the island of Lifou, in the South Pacific. Lifou is a remote island belonging to the archipelago of New Caledonia, localised more than 16000 km away from mainland France. Although officially a French overseas territory, live in Lifou is to a large degree organised according to customary tradition of the indigenous population, the Kanak people. There is no obvious societal majority language on the island and French and Drehu are commonly spoken by the indigenous population, who make up the majority of the inhabitants.

The aim of this examination is to develop a phonetic prosodic model for the two languages and determine whether there are effects of prosodic transfer between the two languages of bilingual speakers. Of particular interest is the the phonetic description of prominence and phrasing of the two languages for a categorisation of their prosodic typology. This thesis presents five studies dealing with (i) the acoustics of Drehu word prosody, (ii) the acoustic correlates of intonational structure in Lifou French, (iii) the acoustic durational properties of Lifou French, (iv) the acoustics of prominence marking and phrasing in Drehu, and (v) acoustic cues used in word recognition in Drehu and French.

The speech and perception data for these studies were collected during four field work trips to the island of Lifou, where more than 100 adult and teenage speakers participated. To investigate processing in the French language and incorporate a monolingual control group, additional experimental work was conducted in the facilities of the Laboratoire Parole et Langage, Aix Marseille University, CNRS, in Aix-en-Provence, in metropolitan France. A variety of methods, typically used in laboratory phonology, such as controlled reading tasks or a forced choice word identification experiment were employed. For exploration and interpretation of the data, all five studies include a statistical analysis.

This work puts forward a revised model of Drehu word prosody and postulates an intonation phonological account of the language. In addition, the intonational phonology of Lifou French is documented, providing the first description of this previously undocumented variety. Building on this descriptive work and taking into consideration previous phonetic research on the speech production and prosody of bilingual speakers, the role of sociolinguistic motivations and functional constraints is discussed. This dissertation highlights the relevance of applying detailed acoustic descriptions to under-documented languages which are poorly understood regarding their prosodic systems. It contributes to the documentation of the languages in the Oceanic region and advances our understanding of bilingual speech processes.