Articulatory Settings of Japanese–English Bilinguals

Articulatory setting, the underlying tendency of the articulators to assume a certain overall configuration during speech, is language-specific and can be measured by observing the inter-speech posture (ISP) of the articulators during the brief pauses between utterances. To determine a given language's ISP, observing bilingual speakers in each of their languages is ideal, so that questionable normalization across different vocal tracts does not have to be done. In this study, four English-Japanese bilinguals of various English proficiencies participated. To this end, we quantitatively tested for the existence of two settings in each bilingual, and the results showed no systematic differences between the tongue ISPs of Japanese and English. We also tried to shed light on the origin of articulatory setting, which is thought to emerge from the configurations of the most frequent phonemes of a language. We qualitatively compared the predicted ISP based on Japanese spoken frequency of occurrence data with the mean measured ISP in Japanese. Ultrasound movies of the tongue were recorded and analyzed, and the results showed that for three participants, the predicted ISP's tongue tip and blade were substantially lower than for the mean measured ISP. The mean measured ISPs also displayed greater variability in English (L2) than in Japanese (L1), much more so in the lower proficiency English speakers.