Third International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications (MAVEBA 2003)

Florence, Italy
December 10-12, 2003

A Formant-Trajectory Model and Its Usage in Comparing Coarticulatory Effects in Dysarthric and Normal Speech

Xiaochuan Niu, Jan P. H. van Santen

Center for Spoken Language Understanding, OGI School of Science & Engineering at OHSU, Beaverton, OR, USA

Dysarthria is a diverse group of motor speech disorders that typically are associated with impaired intelligibility. As part of a project to develop augmentative communication technologies for intelligibility enhancement of dysarthric speech, a quantitative method is proposed for measuring the relative contributions to impaired intelligibility of vowels of three factors: First, target shift: Dysarthric speakers may have spectral targets that differ from those of normal speakers. Second, coarticulation: The degree of contextual influence on articulation may be greater in dysarthric speech than in normal speech. Third, random variability: Dysarthric speakers may articulate the same phoneme in the same context with more variability. The method is based on a linear model of formant trajectories of vowels in consonant contexts. The results from analysis of a dysarthric and a normal speech sample showed surprisingly similar target values, but increased coarticulation and random variability for the dysarthric sample.

Index Terms. Dysarthria, coarticulation, formant

Full Paper (reprinted with permission from Firenze University Press)

Bibliographic reference.  Niu, Xiaochuan / Santen, Jan P. H. van (2003): "A formant-trajectory model and its usage in comparing coarticulatory effects in dysarthric and normal speech", In MAVEBA-2003, 233-236.