Ian R. A. MacKay

Native Italian speakers' perception and production of English vowels

This study examined the production and perception of English vowels by highly experienced native Italian speakers of English. The subjects were selected on the basis of the age at which they arrived in Canada and began to learn English, and how much they continued to use Italian. Vowel production accuracy was assessed through an intelligibility test in which native English-speaking listeners attempted to identify vowels spoken by the native Italian subjects. Vowel perception was assessed using a categorial discrimination test. The later in life the native Italian subjects began to learn English, the less accurately they produced and perceived English vowels. Neither of two groups of early Italian/English bilinguals differed significantly from native speakers of English either for production or perception. This finding is consistent with the hypothesis of the speech learning model [Flege, in Speech Perception and Linguistic Experience: Theoretical and Methodological Issues (York, Timonium, MD, 1995)] that early bilinguals establish new categories for vowels found in the second language (L2). The significant correlation observed to exist between the measures of L2 vowel production and perception is consistent with another hypothesis of the speech learning model, viz., that the accuracy with which L2 vowels are produced is limited by how accurately they are perceived.

Interaction between the native and second language phonetic subsystems

The underlying premise of this study was that the two phonetic subsystems of a bilingual interact. The study tested the hypothesis that the vowels a bilingual produces in a second language (L2) may differ from vowels produced by monolingual native speakers of the L2 as the result of either of two mechanisms: phonetic category assimilation or phonetic category dissimilation. Earlier work revealed that native speakers of Italian identify English/eI/ tokens as instances of the Italian /e/ category even though English /eI/ is produced with more tongue movement than Italian /e/ is. Acoustic analyses in the present study examined /eI/s produced by four groups of Italian-English bilinguals who differed according to their age of arrival in Canada from Italy (early versus late) and frequency of continued Italian use (low-L1- use versus high-L1-use). Early bilinguals who seldom used Italian (Early-low) were found to produce English /eI/ with significantly more movement than native English speakers. However, both groups of late bilinguals (Late-low, Late-high) tended to produced /eI/ with less movement than NE speakers. The exaggerated movement in /eI/s produced by the Early-low group participants was attributed to the dissimilation of a phonetic category they formed for English /eI/ from Italian /e/. The undershoot of movement in /eI/s produced by late bilinguals, on the other hand, was attributed to their failure to establish a new category for English /eI/, which led to the merger of the phonetic properties of English /eI/ and Italian /e/.

Perceiving Vowels in a Second Language.

This study examines the perception of English vowels by native speakers of Italian. In two preliminary experiments, Italian university students who had lived in Canada for 3 months were found to have difficulty discriminating because they often identified both members of each contrast as instances of a single Italian vowel. The participants in two other experiments, long-time residents of Canada, were assigned to groups based on their age of arrival in Canada from Italy (early vs. late) and percentage of first language (L1) use (high L1 use vs. low L1 use). Experiment 3 focused on the discrimination of , and experiment 4 examined the discrimination of correct from incorrect realizations of . In both experiments, the early learners obtained higher discrimination scores than the late learners, and low-L1-use participants obtained higher scores than high-L1-use participants. Most important, the early learners who used Italian often (early high), but not the early learners who used Italian seldom (early low), were found to differ from native speakers of English in perceiving English vowels. These results suggest two important conclusions regarding second language (L2) perceptual learning: Learning an L2 in childhood does not guarantee a nativelike perception of L2 vowels, nor does the establishment of a sound system for the L1 preclude a functionally nativelike perception of L2 vowels. Another important finding is that, although the late learners generally perceived English vowels less accurately than the early learners, some perceived them accurately. This study was supported by grant DC00257 from the National Institute of Deafness and Other Communicative Disorders. The authors thank J. Prosperine and M. Pearse for help locating participants, Fr. M. Brodeur of St. Anthonys Church in Ottawa, Ontario, and all the participants. The authors are grateful to D. Meador and T. Piske for help preparing the stimuli used in experiment 4. Finally, thanks are extended to K. Aoyama, S. Imai, K. Tsukada, T. Piske, and three anonymous SSLA reviewers for comments on an earlier version of this article.

Phonological primitives : electromyographic speech error evidence

Speech error data have been used to argue for the psychological reality of distinctive features and phonemes as well as the hierarchical ordering levels of processing for speech production. The models of production that have emerged from analysis of these data are nearly unanimous in characterizing (implicitly or explicitly) the motor output level as entirely governed by prior selection and processing of larger units, especially the phoneme. This study reports on the laboratory elicitation of sublexical speech errors by means of tongue twisters. Simultaneous audio and electromyographic recordings were analyzed. Where possible, single-motor unit discrimination was carried out to preclude the possibility of signal contamination by activation of adjacent musculature. The results indicate that traditional methods of data collection on which most speech error corpora are based are inadequate. Production models based on these corpora are not supported by the electromyographic data and must accordingly be revised.

The Production of English Vowels by Fluent Early and Late Italian-English Bilinguals

The primary aim of this study was to determine if fluent early bilinguals who are highly experienced in their second language (L2) can produce L2 vowels in a way that is indistinguishable from native speakers’ vowels. The subjects were native speakers of Italian who began learning English when they immigrated to Canada as children or adults (‘early’ vs. ‘late’ bilinguals). The early bilinguals were subdivided into groups differing in amount of continued L1 use (early-low vs. early-high). In experiment 1, native English-speaking listeners rated 11 English vowels for goodness. As expected, the late bilinguals’ vowels received significantly lower ratings than the early bilinguals’ vowels did. Some of the early-high subjects’ vowels received lower ratings than vowels spoken by a group of native English (NE) speakers, whereas none of the early-low subjects’ vowels differed from the NE subjects’ vowels. Most of the observed differences between the NE and early-high groups were for vowels spoken in a nonword condition. The results of experiment 2 suggested that some of these errors were due to the influence of orthography.

Category restructuring during second-language speech acquisition

This study examined the production of English /b/ and the perception of short-lag English /b d g/ tokens by four groups of bilinguals who differed according to their age of arrival (AOA) in Canada from Italy and amount of self-reported native language (L1) use. A clear difference emerged between early bilinguals (mean AOA= 8 years) and late bilinguals (mean AOA= 20 years). The late bilinguals showed a stronger L1 influence than the early bilinguals did on both the production and perception of English stops. In experiment 2, the late bilinguals produced a larger percentage of prevoiced English /b/ tokens than early bilinguals and native English (NE) speakers did. In experiment 3, the late bilinguals misidentified short-lag English /b d g/ tokens as /p t k/ more often than the early bilinguals and NE speakers did. Experiment 4 revealed that the frequencies with which the bilinguals prevoiced /b d g/ in Italian and English were correlated. The observed differences between the early and late bilinguals were attributed to differences in the quantity and quality of English phonetic input they had received, not to a greater likelihood by the early than late bilinguals to establish new phonetic categories for English /b d g/.

The Identification of English Consonants by Native Speakers of Italian

This study examined the identification of English consonants in noise by native speakers of Italian. The effect of age of first exposure to English was evaluated by comparing three groups of subjects who continued to use Italian relatively often but differed according to their age of arrival (AOA) in Canada from Italy (early: 7, mid: 14, late: 19 years). The subjects in the late group made more errors identifying word-initial consonants than subjects in the early group did; however, the effect of AOA was nonsignificant for word-final stops. The effect of amount of native language (L1) use was evaluated by comparing two groups of early bilinguals who were matched for AOA (mean = 7 years) but differed according to self-reported percentage use of Italian (early: 32%, early-low: 8%). The early bilinguals who used Italian often (early) made significantly more errors identifying word-initial and word-final consonants than native English (NE) subjects did, whereas the early bilinguals who used Italian seldom (early-low) did not differ from the NE subjects. The subjects’ phonological short-term memory was estimated by having them repeat Italian non-words. This was done in an attempt to identify the source of individual differences. The nonword repetition scores were in fact found to independently account for 15% of the variance in subjects’ errors identifying word-final English consonants and 8% of the variance for word-initial consonants.

Persistent errors in the perception and production of word‐initial English stop consonants by native speakers of Italian

This study examined the perception and production of word‐initial tokens of English stops (/b d g/ and /p t k/) by native speakers of Italian. The native Italian subjects were assigned to one of four groups based on their age of arrival (AOA) to Canada from Italy and percentage of self‐reported use of the native language, Italian. The results obtained here suggested that AOA was a more important predictor of the native Italian subjects’ perception and production of word‐initial English stops than L1 use was. The results also provided evidence of native versus non‐native differences in segmental perception and production that persisted after decades of frequent second‐language use. As hypothesized, the native Italian subjects produced English /p t k/ more accurately than /b d g/. In a perception experiment examining naturally produced English stops, the native Italian subjects misidentified short‐lag tokens of English /b d g/ as /p t k/ more often than they misidentified long‐lag /p t k/ tokens as /b d g/....

Non‐natives’ production of vowels in conversational speech

The aim of this study was to determine if native speakers of Italian can ever learn to produce accurately English vowels not found in Italian. A recent study [J. E. Flege, I. R. A. MacKay, and D. Meador, J. Acoust. Soc. Am., under review], in which native Italian subjects were asked to repeat real words presented via a loudspeaker, showed that early but not late bilinguals produced English /ɪʊɚ/ accurately. None of the subjects, however, did so when asked to repeat nonwords. But what about the most crucial evidence—conversational speech? Here a new technique with satisfactory experimental control ws developed to assess vowels produced in conversational speech. Speech samples were obtained from the same 90 subjects who participated in the earlier study. The subjects’ production of /ɪʊɚ/ (not found in Italian) and /i ae o/ was evaluated auditorily by native English‐speaking listeners. Preliminary results indicate that early bilinguals can learn to produce /ɪʊɚ/ accurately in conversational speech, but that o...

Nonnatives’ perception of English sentences presented in noise

This study built on earlier investigations of the effects of noise on speech identification by nonnative speakers. Oyama showed that the ability of native Italian subjects to identify speech in noise was inversely related to their age of arrival (AOA) in the United States [J. Psycholinguist. Res. 5, 261–283 (1976)]. Mayberry and Fischer showed that more phonological and fewer semantic errors are made the later sign language is acquired, indicating that late learners allocate more attention to bottom‐up processes [Mem. Cognit. 17, 740–754 (1989)]. Subjects in the present study were native English (NE) and Italian/English bilinguals differing in their AOA in Canada. The stimuli were naturally produced, semantically unpredictable English sentences. Subjects repeated as much of each sentence as possible as it was presented at successively higher S/N ratios (−6, 0, 6, 12 dB). NE subjects outperformed the bilinguals, despite the latter’s lengthy residence in Canada (M=35.4 years). The bilinguals’ performance va...