MRI motion imaging of articulatory movement-coarticulation effects in velar consonants

Abstract

Magnetic resonance imaging (MRI) techniques have been used in speech research for measuring the vocal tract. Recently, MRI motion imaging has been developed and applied to the study of speech production. In this study, the coarticulatory effects of Japanese velar stop consonants were measured using a synchronized sampling method. The MRI technique employed is a synchronized sampling technique which is a modification of one originally developed for cardiac motion imaging. Speech samples consisted of /aka/ and /aki/, including the Japanese velar stop consonant /k/ and vowel /i/, in normal subjects. Results depicted motion of the speech organs in the midsagittal plane. When velar consonants were followed by a back vowel /a/, the back of the tongue contacted the posterior part of the soft palate, and when followed by front vowel /i/, tongue contact was more toward the anterior of the soft palate. Thus the tongue contact position for Japanese velar stop consonants was found to be strongly influenced by the following vowel.