Ultrasound evidence for place of articulation of the mora nasal /ɴ/ in Japanese

Abstract

The Japanese mora nasal /ɴ/, which occurs in syllable-final position, takes its place of articulation from the following segment if there is one. However, the mora nasal in utterance-final position is often transcribed as velar, uvular, or even placeless. The present study examines the tongue shapes in Japanese using ultrasound imaging to investigate whether Japanese mora nasal /ɴ/ is placeless and to assess whether assimilation to following segments is gradient or categorical. Preliminary results from ultrasound imaging from one native speaker of Tokyo dialect showed three shapes for final /ɴ/, even though the researchers could not distinguish them perceptually. Results from assimilation contexts showed that the velar gesture for /ɴ/ was not deleted. All gestures remained and assimilation was not categorical, even though perceptually, it was. The velar gesture for /ɴ/ might be expected to be deleted before an alveolar /n/ because they are both lingual, but a blending of the two tongue gestures occurred instead. Variability in place of articulation in final position occurred even within one speaker. Categorical assimilation was not observed in any phonological environments studied. The mora nasal may vary across speakers, so further research is needed to determine whether it behaves similarly for more speakers.

Representing the moraic nasal in Japanese: evidence from Tōkyō, Ōsaka and Kagoshima

“…Vance (1987Vance ( : 34-35, 2008 provides review of instrumental and acoustic studies which show that uvulo-dorsal closure in intervocalic and pre-pausal position is variable (Nakano 1969: 220, Ushijima & Hirose 1974, Aoki 1976: 204, Kawakami 1977, Uemura & Takada 1990. More recently, closure of the oral tract is discussed by Hashi (2000), Yamane & Gick (2010), Yamane (2013), Mizoguchi & Whalen (2014), Nogita & Yamane (2015), Hashi et al (2016) and Kochetov (2018). Work from Hashi and colleagues (Hashi et al 1998(Hashi et al , 2016 in particular shows that uvular closure during production of final N is in fact often absent, with other possible realisations including a labial nasal or a nasalised vocoid.…”