Non-native speech perception in adverse conditions: A review <s> Input differences <s> The coming of language occurs at about the same age in every healthy child throughout the world, strongly supporting the concept that genetically determined processes of maturation, rather than environmental influences, underlie capacity for speech and verbal understanding. Dr. Lenneberg points out the implications of this concept for the therapeutic and educational approach to children with hearing or speech deficits. <s> BIB001 </s> Non-native speech perception in adverse conditions: A review <s> Input differences <s> Proceedings of the Fifth Annual Meeting of the Berkeley Linguistics ::: Society (1979), pp. 510-524 <s> BIB002 </s> Non-native speech perception in adverse conditions: A review <s> Input differences <s> This article discusses the Critical Period Hypothesis (CPH) as it relates to the naturalistic acquisition of foreign-language (L2) pronunciation by adults and children. An examination of the existing empirical and theoretical literature leads to the conclusion that there is no conclusive support for the existence of a critical period for human speech learning, and that assuming a critical period does exist may inhibit the search for testable hypotheses concerning the basis for observed adult-child differences in L2 pronunciation. These conclusions are based on the existence of direct coullter-evidence, as well as on the observation that apparent adult-child performance differences may arise from many different confounding factors other than adult-child differences in neurological maturation or organization that cannot be adequately controlled in behavioral research. <s> BIB003 </s> Non-native speech perception in adverse conditions: A review <s> Input differences <s> This article reviews the second language research on age-related differences, as well as first language work needed to disambiguate some of the findings. Five conclusions are drawn, (a) Both the initial rate of acquisition and the ultimate level of attainment depend in part on the age at which learning begins. (b) There are sensitive periods governing language development, first or second, during which the acquisition of different linguistic abilities is successful and after which it is irregular and incomplete. (c) The age-related loss in ability is cumulative (not a catastrophic one-time event), affecting first one linguistic domain and then another, and is not limited to phonology, (d) The deterioration in some individuals begins as early as age 6—not at puberty as is often claimed. (e) Affective, input, and current cognitive explanations for the reduced ability are inadequate. The capacity for language development is maturationally constrained, and its decline probably reflects a progressive loss of neural plasticity, itself possibly associated with increasing myelination. <s> BIB004 </s> Non-native speech perception in adverse conditions: A review <s> Input differences <s> Native speakers of Japanese learning English generally have difficulty differentiating the phonemes /r/ and /l/, even after years of experience with English. Previous research that attempted to train Japanese listeners to distinguish this contrast using synthetic stimuli reported little success, especially when transfer to natural tokens containing /r/ and /l/ was tested. In the present study, a different training procedure that emphasized variability among stimulus tokens was used. Japanese subjects were trained in a minimal pair identification paradigm using multiple natural exemplars contrasting /r/ and /l/ from a variety of phonetic environments as stimuli. A pretest‐posttest design containing natural tokens was used to assess the effects of training. Results from six subjects showed that the new procedure was more robust than earlier training techniques. Small but reliable differences in performance were obtained between pretest and posttest scores. The results demonstrate the importance of stimulus ... <s> BIB005 </s> Non-native speech perception in adverse conditions: A review <s> Input differences <s> Two experiments were carried out to extend Logan et al.'s recent study [J. S. Logan, S. E. Lively, and D. B. Pisoni, J. Acoust. Soc. Am. 89, 874-886 (1991)] on training Japanese listeners to identify English /r/ and /l/. Subjects in experiment 1 were trained in an identification task with multiple talkers who produced English words containing the /r/-/l/ contrast in initial singleton, initial consonant clusters, and intervocalic positions. Moderate, but significant, increases in accuracy and decreases in response latency were observed between pretest and posttest and during training sessions. Subjects also generalized to new words produced by a familiar talker and novel words produced by an unfamiliar talker. In experiment 2, a new group of subjects was trained with tokens from a single talker who produced words containing the /r/-/l/ contrast in five phonetic environments. Although subjects improved during training and showed increases in pretest-posttest performance, they failed to generalize to tokens produced by a new talker. The results of the present experiments suggest that variability plays an important role in perceptual learning and robust category formation. During training, listeners develop talker-specific, context-dependent representations for new phonetic categories by selectively shifting attention toward the contrastive dimensions of the non-native phonetic categories. Phonotactic constraints in the native language, similarity of the new contrast to distinctions in the native language, and the distinctiveness of contrastive cues all appear to mediate category acquisition. <s> BIB006 </s> Non-native speech perception in adverse conditions: A review <s> Input differences <s> Monolingual speakers of Japanese were trained to identify English /r/ and /l/ using Logan et al.’s [J. Acoust. Soc. Am. 89, 874–886 (1991)] high‐variability training procedure. Subjects’ performance improved from the pretest to the post‐test and during the 3 weeks of training. Performance during training varied as a function of talker and phonetic environment. Generalization accuracy to new words depended on the voice of the talker producing the /r/–/l/ contrast: Subjects were significantly more accurate when new words were produced by a familiar talker than when new words were produced by an unfamiliar talker. This difference could not be attributed to differences in intelligibility of the stimuli. Three and six months after the conclusion of training, subjects returned to the laboratory and were given the post‐test and tests of generalization again. Performance was surprisingly good on each test after 3 months without any further training: Accuracy decreased only 2% from the post‐test given at the end o... <s> BIB007 </s> Non-native speech perception in adverse conditions: A review <s> Input differences <s> Contents: Preface. D. Birdsong, Introduction: Whys and Why Nots of the Critical Period Hypothesis for Second Language Acquisition. C.M. Weber-Fox, H.J. Neville, Functional Neural Subsystems Are Differentially Affected by Delays in Second Language Immersion: ERP and Behavioral Evidence in Bilinguals. J.R. Hurford, S. Kirby, Co-Evolution of Language Size and the Critical Period. L. Eubank, K.R. Gregg, Critical Periods and (Second) Language Acquisition: Divide et Impera. J.E. Flege, Age of Learning and Second Language Speech. T. Bongaerts, Ultimate Attainment in L2 Pronunciation: The Case of Very Advanced Late L2 Learners. E. Bialystok, K. Hakuta, Confounded Age: Linguistic and Cognitive Factors in Age Differences for Second Language Acquisition. <s> BIB008 </s> Non-native speech perception in adverse conditions: A review <s> Input differences <s> At the forefront of debates on language are new data demonstrating infants' early acquisition of information about their native language. The data show that infants perceptually “map” critical aspects of ambient language in the first year of life before they can speak. Statistical properties of speech are picked up through exposure to ambient language. Moreover, linguistic experience alters infants' perception of speech, warping perception in the service of language. Infants' strategies are unexpected and unpredicted by historical views. A new theoretical position has emerged, and six postulates of this position are described. <s> BIB009 </s> Non-native speech perception in adverse conditions: A review <s> Input differences <s> Previous research has suggested that child but not adult immigrants to the United States and ::: Canada make regular progress learning English as their length of residence (LOR) increases. If ::: children and adults received the same kind of second language (L2) input, such evidence would ::: support the existence of a critical period for L2 acquisition. The present study compared groups ::: of Chinese adults living in the United States who differed in LOR in order to assess the role of ::: input in adults' naturalistic acquisition of an L2. We assessed the Chinese ::: participants' identification of word-final English consonants (experiment 1), their scores on ::: a 144-item grammaticality judgment test (experiment 2), and their scores on a 45-item listening ::: comprehension test (experiment 3). The Chinese participants were assigned to one of four groups ::: ( n = 15 each) based on LOR in the United States and their primary occupation ::: (students vs. nonstudents). Significantly higher scores were obtained for the students with ::: relatively long LORs than for the students with relatively short LORs in all three experiments. ::: However, the difference between the nonstudents differing in LOR was nonsignificant in each ::: instance. The results suggested that the lack of an effect of LOR in some previous studies may ::: have been due to sampling error. It appears that adults' performance in an L2 will improve ::: measurably over time, but only if they receive a substantial amount of native speaker input. <s> BIB010 </s> Non-native speech perception in adverse conditions: A review <s> Input differences <s> Infants learn language with remarkable speed, but how they do it remains a mystery. New data show that infants use computational strategies to detect the statistical and prosodic patterns in language input, and that this leads to the discovery of phonemes and words. Social interaction with another human being affects speech learning in a way that resembles communicative learning in songbirds. The brain's commitment to the statistical and prosodic patterns that are experienced early in life might help to explain the long-standing puzzle of why infants are better language learners than adults. Successful learning by infants, as well as constraints on that learning, are changing theories of language acquisition. <s> BIB011
A key difference between L1 and L2/FL acquisition is the starting point of language acquisition. The critical period hypothesis BIB001 maintains that after a certain point in a person's maturation process, the ability to learn languages to a native-like standard is lost. The current consensus view is that, although it is not impossible to achieve native-like performance after a particular age, it is the case that for most individuals, native-like competence, and in particular native-like phonological competence is not possible if languages are learned after childhood. Puberty has traditionally been considered to be the cut-off point  , although it is currently believed that different linguistic abilities may have different sensitive periods, and that speech is the earliest  BIB002 . By 4-6 months of age, infants show preferences for the sounds of their native language  or for languages rhythmically similar to their L1  . The reasons given for a sensitive period for languages have ranged from loss of brain plasticity or neurological specialisation BIB001 BIB004   BIB002 to deep-seated L1 habits BIB003 BIB008  . BIB009 BIB011 offers a comprehensive account in which both neurological and input factors account for the age factor. In her view, exposure to the L1 very early on creates neural patterns corresponding to what has been learned and these patterns then act as a filter which interferes in the processing of later stimuli which differ from the established patterns. Another important difference between L1 and L2/FL acquisition which bears on the configuration of the TL sound system is the amount of exposure BIB010 . The amount of native speech input obtained varies with the age of the learners and their occupation and social contacts. In general, late learners do not receive as much native speech input as natives and early bilinguals, who interact abundantly through school and other activities from the beginning whereas adult immigrants are more likely to maintain contact with other L1 speakers. Quantity can be viewed as a scale ranging from minimal aural exposure (e.g. old-fashioned FL teaching methods based solely on grammar and translation) to total immersion in the TL natural context, with 100% of the learners' speech interaction being carried out in the TL. An L2 acquisition context is a necessary but not sufficient condition for the latter. Another factor which differentiates L1 from later language acquisition is the quality and diversity of the input, ranging from single-source, non-native, heavily L1accented pronunciations of the TL found in some FL learning situations to diverse, native and variable speech characteristic of natural contexts. Training studies have shown that for the formation of robust categories, diverse native input is necessary, which is the basis of the high-variability training methods introduced by Pisoni and his colleagues BIB005 BIB006 BIB007 . It is notable that there have been few studies of the effect of simulated adverse conditions on training.