Oral/nasal airflow during Japanese stop consonants

Abstract

Voiced obstruents have inherent susceptibility for devoicing due to the Aerodynamic Voicing Constraints (AVC), and the susceptibility is higher for geminate obstruents than singletons. As a way to investigate how Japanese speakers realize the contrast between the [ + /-voice] contrast in obstruents, we examined oral and nasal airflow patterns during intervocalic voiced and voiceless stops, in singletons and geminates. The results showed asymmetry between single and geminate stops in realization of the stop voicing contrast. Airflow pattern clearly differentiates voiced vs. voiceless contrast in singletons, but the airflow patterns are similar in geminates. Acoustic signals also shows the same asymmetry between the singletons and geminates. The observed convergence—clear voicing contrast in singletons vs. the lack of the contrast in geminates both in air flow and acoustic signals indicate neutralization of the voiced geminates into voiceless ones. Our results support the idea of phonetic bases in phonological patterning of voicing neutralization in Japanese geminate stops.

Partial devoicing of voiced geminate stops in Tokyo Japanese

“…geminate stops of Tokyo Japanese. While the status of voiced geminates is marginal in Tokyo Japanese, and partial neutralization with voiceless geminates has been reported (Fujimoto and Kataoka, 2016;Kawahara, 2006Kawahara, , 2015Kawahara, , 2016, we observed that some acoustic attributes, particularly vowel durations preceding the geminates, still differentiate them. This suggests that the contrast between voiceless and voiced geminate stops in Tokyo Japanese is not completely neutralized.…”

“…However, other forms that avoid voiced geminates, such as /betto/ "bed" (the variant of /beddo/), /bakku/ "bag" (the variant of /baggu/), and /robu/ "Rob" (without gemination), are also currently used. Together with some phonetic evidence implying neutralization of voiced geminates with voiceless geminates reported in previous studies (Fujimoto and Kataoka, 2016;Hirose and Ashby, 2007;Kawahara, 2005Kawahara, , 2006; details of these studies are introduced below), the existence of variant forms avoiding voiced geminates leaves us in doubt whether voiced geminate stops are an established phonological category in Tokyo Japanese. Although voiced geminates are banned in the native vocabulary, there seems to be a driving force to level voiceless and voiced geminate stops in loanwords.…”

“…Kirchner (1998) claimed that the production of voiced geminates requires more articulatory effort than voiceless geminates. Fujimoto and Kataoka (2016) provided oral airflow data indicating that only the voiceless and voiced singletons (/t/ vs /d/) of Tokyo Japanese are clearly differentiated, but voiceless and voiced geminates (/tt/ vs /dd/) are not. It is still unclear how voicing contrast is manifested in the acoustics of voiced geminate stops in Tokyo Japanese.…”