Speech perception abilities in early and late bilinguals

Among the early L2 learners we can distinguish between sequential and simultaneous bilinguals. Early L2 learners can be contrasted to late L2 learners who learned their second language relatively late in life. How do early and late L2 learners compare to native speakers in terms of reaching proficiency in L2?  In quiet, L2 speakers show the same performance as native speakers in speech perception tasks (e.g. Nabelek & Donahue, 1984) while in background noise,  their speech perception in the second language is more affected than in the first language (Florentine, 1985a, b; Takata & Nabelek, 1990). This effect has been suggested to relate to listeners’ age (Bergman, 1980), the time-period of L2 study (Florentine, 1985a, b), and the environmental situation under which listening occurs (Takata & Nabelek, 1990).

Research by Florentine (1985b) showed that exposure to L2 from infancy onwards helped two L2 listeners to perform as well as L1 speakers on speech perception tasks in the presence of increasing noise. By contrast, L2 listeners who had been exposed to L2 only after puberty did not perform at the same level as L1 listeners of American English even after massive exposure. Moreover, L2 listeners did not make use of any contextual cues, which contrasts to the effects seen in L1 listeners. These data are interpreted as indicating a sensitive period after which learning a second language negatively affects L2 listeners’ perception of L2 in noise. Thus, in noise, L2 speakers’ performance on speech perception tasks has been shown to depend on the age at which they acquire L2 (Florentine, 1985b; Mayo et al., 1997).

It was shown that in speech perception tasks with noise, early learners of L2 performed better and benefitted more from sentence-level contextual information compared to late but very proficient L2 learners. However, early L2 learners’ ability to perceive L2 in noise has been suggested to be decreased and not be like that of native listeners’ due to intervention by L1 experience (Mayo et al., 1997). It has therefore been argued that early L2 learners’ better performance might be due to the age at which L2 was acquired and not the average time length of L2 exposure. Consequently, if L2 study is not started in early childhood, L2 listeners will have difficulty perceiving L2 in noise even with extensive exposure. This has been illustrated by early L2 learners showing higher levels of tolerating noise than late L2 learners. However, L1 English listeners had higher noise-tolerance levels than early L2 learners of English (Mayo et al., 1997).  L1 listeners have thus been claimed to recover quickly from noise-induced disturbance because of their linguistic knowledge of established L1 categories (Bradlow & Alexander, 2007). On the contrary, late L2 learners are not able to recover their speech perception that is disrupted by noise as quickly as L1 listeners because their lacking linguistic knowledge of L2 causes their recovery from noise to be too slow (Bradlow & Alexander, 2007).

Does this mean that late L2 learners will not be able to attain nativelike L2 proficiency? Luckily, findings that found nativelike attainment in L2 late learners, and non-native like attainment in early L2 learners suggest the answer is no (Birdsong, 1999, 2006; Bongaerts, 1999). For example, a study, in which native Vietnamese early and child learners of English were tested on a grammaticality judgement task, showed how they did not perform better or worse than native English speakers (MacDonald, 2000). Specifically, early Vietnamese learners were revealed to have lasting grammatical accents as well, suggesting that some early L2 learners do not show nativelike proficiency at all. One can therefore say that it is not certain that nativelike proficiency will result from an early exposure to a second language. In another study, native English speakers were asked to rate the English speech samples for accent that had been produced by L1 Dutch speakers who started learning English at about the age of 12 (Bongaerts, 1999). About half of these proficient learners of English were mistaken for native speakers of English suggesting that it is possible for late L2 learners to attain proficiency similar to native speakers with regard to pronunciation. This possibility of successful late learning of a second language was further supported by studies that replicated the previous study with learners of languages that are not closely related to L1 such as proficient Dutch L1 learners of French (Bongaerts, 1999), and late learners of Hebrew who had a different native language (Abu-Rabia & Kehat, 2004). Thus, an early start in learning a second language is not prerequisite in acquiring unaccented speech in L2.

Physiological evidence provided additional support in form of a study, in which it was shown how a group of adult participants who were trained on an artificial language demonstrated a similar pattern of brain activation during the processing of that language that is observed when native speakers process a natural language (Friederici et al., 2002). In particular, the observations of early negativity and late positivity (N400 and P600) as elicited by syntactic violations imply the processes of swift automatic parsing, and decelerated repair and reanalysis that are also observed during native speakers’ processing of syntactic violations. This finding seems to suggest that both early and late learners of a language make use of the same brain mechanism during the processing of that language. These results are supported by other ERP studies that have shown ERP patterns evoked in fluent L2 users that are largely observed in native speakers as well (Hahne & Friederici, 2001) while differences in ERP patterns were revealed when native and non-proficient speakers’ processing was compared (Ojima et al., 2005). Similarly, brain imaging studies found the same brain areas being activated when fluent L2 speakers and native speakers process a language (Perani et al., 1998) while brain activation in different regions were observed when native and non-proficient speakers’ processing was compared (Dehaene et al. 1997).

Can you become bilingual?

The observation that our ability to learn speech in different languages does remain functional over the course of life is good news for all of us who recently thought of taking up a second language. No matter what your age is, or which language you considered of learning, as long as you create yourself the ideal environment for you to learn a second language, with effort it is possible. For example, I learnt my second language after learning my first language; hence I am a sequential bilingual. The fact that both languages were rhythmically different languages and do not share the same sound system, helped me with learning both languages more efficiently, and to this day I am still learning bits and pieces in these two languages that help me understand how I can refine my communication skills. The learning therefore never stops! Thus, when you train yourself intensively in perceiving and producing the sounds of the second language, show the motivation and enthusiasm to sound nativelike, with massive L2 input, it will be possible for you to achieve your aim of becoming a fluent L2 speaker. 

References

 

Abu-Rabia, S., & Kehat, S. (2004). The critical period for second language pronunciation: Is there such a thing? Ten case studies of late starters who attained a native-like Hebrew accent. Educational Psychology, 24, 77-98.

Bergman, M. (1980). Aging and the perception of speech. Baltimore: University Park Press.

Birdsong, D. (1999). Introduction: Whys and why nots of the critical period hypothesis for second language acquisition. In D. Birdsong (Ed.), Second language acquisition and the critical period hypothesis (pp. 1-22). Mahwah, NJ: Erlbaum.

Birdsong, D. (2006). Age and second language acquisition and processing: A selective overview. Language Learning, 56, 9-48.

Bongaerts, T. (1999). Ultimate attainment in L2 pronunciation: The ease of very advanced late L2 learners. In D. Birdsong (Ed.), Second language acquisition and the critical period hypothesis (pp.133-149). Mahwah, NJ. Erlbaum.

Dehaene, S., Dupoux, E., Mehler, J., Cohen, L., Paulesu, E., Perani, D., et al. (1997). Anatomical variability in the cortical representation of first and second language. NeuroReport, 8, 3809-3815.

Florentine, M. (1985a). Non-native listeners’ perception of American-English in noise. Proceedings of Inter-Noise ’85, 1021-1024.

Florentine, M. (1985b). Speech perception in noise by fluent, non-native listeners. Proceedings of the Acoustical Society of Japan. H-85-16.

Hahne, A., & Friederici, A. D. (2001). Processing a second language: Late learners’ comprehension mechanisms as revealed by event-related brain potentials. Bilingualism: Language and Cognition, 4, 123-141.

 

Mayo, L. H., Florentine, M., & Buus, S. (1997). Age of second-language acquisition and perception of speech in noise Journal of Speech, Language & Hearing Research, 40, 686–93.

McDonald, J.L. (2000). Grammaticality judgements in a second language: Influences of age of acquisition and native language. Applied Psycholinguistics, 21, 395-423.

Nabelek, A.K., & Donahue, A.M. (1984). Perception of consonants in reverberation by native and non-native listeners. Journal of Acoustical Society of America, 75, 632-634.

Ojima, S., Nakata, H., & Kakigi, R. (2005). An ERP study of second language learning after childhood: Effects of proficiency. Journal of Cognitive Neuroscience, 17, 1212-1228.

Perani, D., Paulesu, E., Sebastian-Galles, N., Dupoux, E., Dehaene, S., Bettinardi, V., et al. (1998). The bilingual brain: Proficiency and age of acquisition of the second language. Brain, 121, 1841-1852.

Takata, Y., & Nabelek, A.K. (1990). English consonant recognition in noise and in reverberation by Japanese and American listeners. Journal of Acoustical Society of America, 88, 663-666.