The production of voice onset time (VOT) by English-speaking children in a Japanese immersion program*

Headnote

Abstract

This study analyzed the production of voice onset time (VOT) for /p, t, k/ in Japanese and English by English-speaking children (n = 15) in a Japanese immersion program. The immersion children produced Japanese voiceless stops with significantly longer VOT values than the monolingual Japanese children and the immersion teachers, but they produced them with significantly shorter VOT values than their English VOT. This suggests that the immersion students are making a phonetic distinction in VOT between Japanese and English, though their VOT values are still intermediate, compared with the norms of the monolingual speakers and their immersion teachers. In other words, the immersion children implemented the VOT contrast differently from the model they were exposed to, that is, that of the Japanese English bilingual teachers.

1. Introduction

Many previous studies have claimed that the earlier children are exposed to a second language in a naturalistic setting, the more likely they are to acquire nativelike pronunciation1 (Flege 1988, 1991, 1992; Oyama 1976; Patkowski 1990, 1994; Scovel 1969, 1988, 1995); however, very little acoustic research gives us any clue as to how early exposure in a classroom situation affects the acquisition of second language speech and more specifically, to what extent children in an early immersion program starting in kindergarten reach the norm of the target language users, that is, their immersion teachers. This is a study on the acquisition of voice onset time (VOT) of phrase initial voiceless stops in Japanese by English-speaking children in a Japanese immersion program.

In the sections that follow, the relationship between the age factor and the production of VOT, including some of the hypotheses of Flege's (1995) Speech Learning Model, is discussed. Then, the phonetic difference between Japanese and English VOT is briefly described. Finally, the effect of immersion programs on the acquisition of pronunciation by children is provided.

2. The age factor and the production of VOT

VOT is defined as "the duration of the time interval by which the onset of periodic pulsing either precedes or follows release" (Lisker and Abramson 1964: 387). Acoustically, aspiration is defined as voice onset delay. In addition, VOT, represented as either negative VOT values standing for "voicing lead (onset of glottal vibration prior to articulatory release)" or positive VOT...