Volume 53, Issue 3

This study examines the acquisition of the phonetic implementation of English final stops by two groups of French speakers. Investigated are parameters which demand a high degree of accuracy in the timing of the sequential movements of the glottal and supraglottal articulators. Rate of acquisition is found to be high for absolute vowel durations and unaspirated final stop release bursts. It is lower for flapping of alveolar stops and relative vowel durations, and it is lowest for extra-short stop closures and short-lag realization of voiced stops. The results confirm those obtained for initial stops. The factors facilitating the acquisition of L2 segments with close counterparts in L1 are the degree of perceptual salience of the various subsegmental intervals and the existence in L1 of allophonic variants similar in realization to the L2 segment. Acquisition begins with the positive transfer of these variants to L2 and their distributional extension to new contexts. In the presence of facilitating factors, it is restricted to the first few years of L2 exposure. In their absence, it requires longer exposure and is limited. Acquisition also strongly depends on individual factors.

The aim of this study was to assess the effect of speaking rate changes on the perception of English stop consonants by four groups of subjects: English and Spanish monolinguals, ‘early’ Spanish/English bilinguals who learned English in childhood, and ‘late’ bilinguals who learned English in adulthood. Subjects identified, and then later rated for goodness as exemplars of the English /p/ category, the members of two voice onset time (VOT) continua. The English monolinguals identified a well-defined range of VOT stimuli as English /p/, and stimuli with longer VOT values as ‘exaggerated’ instances of English /p/. Their goodness ratings increased as VOT increased, then showed a systematic decrease as VOT began to exceed values typical for English /p/. The English monolinguals’ goodness ratings also varied systematically as a function of speaking rate, which was simulated in the two continua by varying syllable duration. The Spanish monolinguals, on the other hand, failed to consistently identify any of the stimuli as English /p/. Although speaking rate influenced their goodness ratings, the Spanish monolinguals’ rate effects differed significantly from the English monolinguals’. The early bilinguals resembled the English monolinguals, and differed from the Spanish monolinguals to a greater extent than did the late Spanish/English bilinguals. This was taken as support for the hypothesis that early bilinguals are more likely than are late bilinguals to establish new phonetic categories for stop consonants in a second language.

Four groups of 10 subjects each (English and Spanish monolinguals, and two groups of Spanish/English bilinguals) produced Spanish or English sentences at speaking rates designated ‘normal’, ‘slow’, and ‘fast’. Voice onset time (VOT) was measured in word-initial tokens of /p/ and /t/ found in sentence-initial, -medial, and -final words. The four groups produced comparable changes in sentence duration across the three rates. The speaking rate changes exerted less effect on the VOT in stops spoken by the Spanish than the English monolinguals. Moreover, whereas English monolinguals produced /p, t/ (with shorter VOT at a fast than at a normal rate, many Spanish monolinguals showed a trend in the opposite direction. As expected, all 10 early bilinguals produced English stops with VOT values that were similar to the English monolinguals’. They also showed speaking rate effects on VOT that were similar to those observed for the English monolinguals. The late bilinguals, who had begun learning English as adults, showed smaller effects of speaking rate on VOT than did the English monolinguals. Their mean VOT values for English stops spanned a wide range of values. Just 3 of the late bilinguals produced English stops with VOT values that fell within the range of values observed for the English monolinguals.