Listener adaptive characteristics of vowel devoicing in Japanese dialogue

Abstract

Listener adapative characteristics of Japanese vowel devoicing were investigated by analyzing (i) dialogues between professional teachers and hearing-impaired (HI) or normal-hearing (NH) children, and (ii) speech samples read by the teachers as fast and clearly as possible (RD). The teachers reduced the devoicing rate and lengthened the moras more in the HI vs NH samples, and even more in the HI vs RD samples. A logistic regression analysis of the devoicing rate suggests that the speech rate dependency of the devoicing rate is different among the HI, NH, and RD samples. When moras are lengthened, the predicted devoicing rate decreases more for the HI vs NH samples, and even more in the HI vs RD samples, suggesting that not only rate-dependent adjustments but also rate-independent adjustments significantly affect devoicing reduction. These results suggest the following: (1) Professional teachers of hearing-impaired children reduce their devoicing not only by lengthening the interval of successive voicing/devoicing gestures, but also by resizing component gestures to some extent, probably to improve the listener's comprehension; (2) vowel devoicing should be represented in terms of parameters of speech motor control; (3) it may be possible to develop an optimized communication method for hearing-impaired children by simulating such listener-adaptive adjustments in speech production.

Speaking Rate Effects on Stops Produced by Spanish and English Monolinguals and Spanish/English Bilinguals

“…1986: Imaizumi et al, 1995. For example, a wide range of acoustic-phonetic dimensions change when one attempts to speak clearly, as in the presence of noise.…”

Misperception of Japanese words with devoiced vowels and/or geminate consonants by young and elderly listeners

“…On the other hand, Fais et al reported that vowel devoicing occurs in infant-directed speech in Japanese as well as in adult speech, although they hypothesized that the devoicing rate decreases when mothers speak to their babies for language acquisition purposes [5]. However, it has also been reported that the rate of devoicing vowels is lower when teachers speak to hearing-impaired children, although vowel devoicing also occurs in adult speech [6].…”

Development of adaptive phonetic gestures in children: Evidence from vowel devoicing in two different dialects of Japanese

“…The degree of articulatory-acoustic variation due to the coproduction of gestures depends both on the extent to which overlapping gestures share articulators, and on the extent of their temporal overlap or blending. The gestural account of vowel devoicing explains this phenomenon as the articulatory-acoustic consequence of the voicing gestures for the intermediate vowel hidden by, or blended with, the devoicing gestures for any surrounding voiceless consonants ͑Jun and Beckman, 1993;Imaizumi et al, 1995͒.…”

“…There has been a lively controversy, however, as to whether vowel devoicing should be described as allophonic variation ͑Hirose, 1971; Yoshioka, 1981͒ or as a lower-level coarticulatory effect ͑Jun and Beckman, 1993;Imaizumi et al, 1995͒. This controversy results from the fact that the probability of such devoicing is dependent on phonological factors ͑Sakuma, 1929; Shibata, 1955;Han, 1962a, b;Sugito and Hirose, 1988͒, phonetic factors ͑Kuriyagawa and Sawashima, 1989;Jun and Beckman, 1993͒, pragmatic factors ͑Imaizumi et al, 1995͒, and dialectal conditions ͑Sugito, 1969 The present paper describes the development of vowel devoicing in childhood as an adaptive organization of the laryngeal gestures rather than a symbolic selection of allophones.…”

“…The main issue tested is whether it is possible to predict developmental changes in vowel devoicing based on the natural improvement in the dialect-specific organization of the laryngeal gestures. For this purpose, two dialects of Japanese were analyzed: the Osaka dialect, which is known to have a low devoicing rate, and the Tokyo dialect, which is known to have a high devoicing rate ͑Sugito, 1969 In several previous studies on vowel devoicing ͑Jun and Beckman, 1993;Imaizumi et al, 1995͒, the concept of ''gesture'' has been adopted as formally defined in the articulatory phonology of Browman and Goldstein ͑e.g., 1986, 1989a, b, 1990. The degree of articulatory-acoustic variation due to the coproduction of gestures depends both on the extent to which overlapping gestures share articulators, and on the extent of their temporal overlap or blending.…”