ISCA International Workshop on Speech and Language Technology in Education (SLaTE 2009)

Wroxall Abbey Estate, Warwickshire, England
September 3-5, 2009

Voice Morphing and the Manipulation of Intra-Speaker and Cross-Speaker Phonetic Variation to Create Foreign Accent Continua: A Perceptual Study

John Ingram (1), Hansjörg Mixdorff (2), Nahyun Kwon (1)

(1) School of EMSAH, University of Queensland, Brisbane, Australia
(2) Department of Informatics and Media, BHT University of Applied Sciences, Berlin, Germany

The STRAIGHT system of voice morphing was used to create voice continua of (Korean) accented Australian English, intended to simulate phonetic variation ranging from ‘heavily accented’ to ‘unaccented’ (native-like) Australian English, employing dimensions of intra-speaker and cross-speaker variation to yield a range of synthetic voices. These synthetic voices were evaluated against actual samples of Korean accented English, both re-synthesized and non-re-synthesized, in a series of three perceptual rating experiments by native listeners of Australian English. The questions of central interest in this preliminary investigation are: (a) the method of creating the phonetic continua and the respective roles of intra- versus cross-speaker variability in simulating degrees of foreign accent, (b) the success of the STRAIGHT method for creating hybrid voices, compared with ‘natural’ tokens of accented utterances, and (c) the impact of the re-synthesis method (required for voice morphing) upon perceptual ratings of foreign accent by native listeners.
   The ultimate objective of this research is to assess the impact of segmental and prosodic features on the perception of foreign accent and intelligibility of L2 learners’ speech, where the source (Korean) and target (English) languages pose significant difficulties of segmental and prosodic transfer.

Full Paper

Bibliographic reference.  Ingram, John / Mixdorff, Hansjörg / Kwon, Nahyun (2009): "Voice morphing and the manipulation of intra-speaker and cross-speaker phonetic variation to create foreign accent continua: a perceptual study", In SLaTE-2009, 145-148.