Speech Production Accuracy Research Articles

The Word Unit in Second Language Speech Production and Perception

The purpose of this study, which focused on the wordtacoas spoken in Spanish and English, was to explore the word as a unit in second language (L2) speech acquisition. As expected, acoustic measurements revealed that Spanish and English monolinguals' renditions oftacodiffered systematically. It was also shown that the extent to which Spanish/English bilinguals approximated English phonetic norms for any one segment oftacowas correlated with their approximation for the other three segments, and that early learners differentiated Spanish versus Englishtacomore than did late learners. It also appeared that the bilinguals produced /t/ with less English-like voice onset time (VOT) values in Englishtacothan in other English words without a cognate in Spanish. In a perception experiment, listeners were able to identify the native language of Spanish and English monolinguals on the basis of their production oftaco. The listeners heard larger differences between Spanish and Englishtacotokens spoken by early than late learners of English L2. Two additional perception experiments assessed further the phonetic dimensions that listeners use to determine language identity and to gauge bilinguals' speech production accuracy. Listeners assigned to language identification and goodness rating tasks responded to acoustic information distributed over all four segments intaco, although the VOT of the word-initial /t/ appeared to be the single most important phonetic dimension. Taken together, the results of this study suggest that (a) bilinguals' accuracy in producing the various segments of a second language word may be interrelated and (b) in judging L2 speech, listeners respond to phonetic errors distributed over the entire word.

Early Speech Production of Children with Cleft Palate

Word-initial target phonemes and the production of those phonemes were examined in normal children and children with cleft palate during the period when the children were acquiring their first 50 words. As a group, the children with cleft palate tended to target more words with word-initial nasals, approximants, and vowels ([ +sonorant] phonemes) and fewer words with word-initial stops, fricatives, and affricates ([-sonorant] phonemes). Normal children tended to target more words with initial consonants articulated in the center of the oral tract ([+coronal]) and the children with cleft palate targeted more words with initial phonemes articulated at the periphery of the oral tract ([-coronal]). The same patterns also were observed in production, but individual children with cleft palate did not always follow this pattern. Although the accuracy of the productions of individual children appeared to be related to word choice, factors such as hearing sensitivity, structural adequacy, and the timing of surgical repair also might have affected speech production accuracy.