Abstract

The purpose of this study was to examine the correlation between acoustic and kinematic measures of diphthong production in 11 individuals with multiple sclerosis (MS) and 11 neurologically healthy control speakers. The participants produced four diphthongs: /ɔɪ/, /aʊ/, /aɪ/, /eɪ/. These sounds were spoken in a sentence context. Their speech audio signal was recorded with a microphone and their tongue movements were recorded with a magnetic tracking system. The first and second formants (F1 and F2) were computed with acoustic analysis software, and these signals were time-aligned with the vertical and anteroposterior magnet movement records. Pearson correlations between F1 and the magnet's vertical movement and between F2 and anteroposterior movement were computed for the individual diphthongs. The results of this study revealed an often non-linear relationship between the acoustic and kinematic measures. The degree to which the formant measures predicted the lingual movements varied across speakers and also during the on-glide, transition, and off-glide phases of the diphthongs. The findings of this study suggest that the relationship between formants and tongue movements is more complex than would be predicted from the theoretical origins of F1 and F2. Thus, researchers should be aware that acoustic parameters might not always accurately reflect the physical movements of articulators.

Degree

College and Department

David O. McKay School of Education; Communication Disorders

Rights

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