Effects of syllable position and vowel context on Japanese /r/: Kinematic and perceptual data

Abstract

In order to investigate the articulatory processes involved in producing Japanese /r/, we obtained speech recordings for native talkers of standard Japanese using an electromagnetic articulography (EMA) system. Each talker produced repetitions of /r/ in a carrier phrase designed to contrast syllable (CV and VCV VCV) and vowel (/a/, /i/, /u/, /e/, and /o/) contexts. Kinematic recordings were made using tongue (tip, TT; dorsum, TD; body, TB; left lateral, TLL; and right lateral, TRL) and lower lip/jaw (LL) sensors. We measured TT vertical displacement, TT duration at maximum position, and tongue blade width for the consonant gestures. In a perceptual experiment, American English listeners decided whether these consonants consisted of 'l,' 'r,' or 'd.' The kinematic results indicate Japanese talkers produced CV consonants with greater stricture and longer closures than consonants in intervocalic positions. CV productions also had narrower tongue blade widths than VCV VCV productions, especially in /i/ and /u/ contexts. The data were modeled with Dirichlet regression in order to determine how strongly tongue width and context (syllable and vowel) factors predict listeners' judgments. The results showed a significant fit for 'r' judgments, with the tongue width fit successively increased by the addition of syllable and vowel context information.