RI: Collaborative Research: Foreign accent conversion through articulatory inversion of the vocal-tract frontal cavity

Texas A&M Engineering Experiment Station, College Station TX

Investigators

Abstract

The ability to transform a ?foreign? accented voice into its ?native? counterpart could be an invaluable tool in pronunciation training for second-language learners. This requires separating those aspects of the speech signal that are determined by the anatomy of the vocal tract from those that result from the idiosyncratic way in which the speaker controls it. While these two sources interact in complex ways in the acoustic domain, a few studies indicate that they may be decoupled in the articulatory space, specifically in the vocal tract frontal cavity. The objective of this research is to determine the extent to which foreign-accent conversion can be performed through articulatory inversion of the frontal cavity. For this purpose, two complementary problems are being investigated. First, existing articulatory datasets are being used to develop a foreign-accent conversion model that operates in the frontal cavity domain. Second, articulatory inversion models are being developed to estimate the frontal cavity configuration from speech acoustics. Results from these models are being systematically validated through perceptual tests of foreign-accentedness, speaker identity and acoustic quality. English is a second language for a significant percentage of the workforce in the United States. Reduction of foreign accent becomes increasingly difficult beyond the ?critical period? of language learning, but substantial improvements in pronunciation do occur for adult second-language learners. This work will stimulate the development of new technology to facilitate such improvements. Its results may also find application for film dubbing/looping, as well as in speech technology at large (e.g., feature extraction, data compression).