Non-native speech perception in adverse conditions: A review <s> The non-native listener <s> An aqueous fluid for the working of metals comprising an aqueous solution of at least one salt of an amido acid of the formula: R-C-NH-CH-(CH2)n-COOH PARALLEL ¦ O(CH2)n'-COOH in which R is a hydrocarbon group, substituted or not by chlorine, and having between 9 and 25 carbon atoms; n and n' are whole numbers or zero, identical or not, whose sum (n + n') is equal to 1 or 2. <s> BIB001 </s> Non-native speech perception in adverse conditions: A review <s> The non-native listener <s> This work is concerned with the acquisition of the phonetic characteristics of languages and dialects, and with the issue of learner talent or individual achievement in learning second languages. Following a survey of the literature on language learning limits, it is argued that the concentration on group trends in most of the existing literature, whilst convenient, serves more to obscure the reasons for the difficulties experienced by most non-child language learners than to explain them. A model of acquisition and communication combining both acquisition and sociolinguistic theory is presented. The central argument of the model is the view that most acquisition and use of the phonetic and phonological characteristics of a language occurs within an imitative (modelling and response) framework. The development of language skills in the infant and child and the acquisition of the first language is discussed. The interaction of established perceptual and productional representations with new phonetic input is also examined in terms of bilingualism, accent mixing and accent change. The concept of foreign accent is described in light of cultural and scientific differences in definition. It is argued that foreign accent is very much in the ear of the beholder, as listeners impose expectations and pronunciation or stylistic norms which the non-native speaker (or other native speakers) may not have been exposed to, or have mastered. It is also observed that listeners’ judgements of accent are susceptible to the influence of other factors such as information about the speaker, the experimental task, or the presence of specific errors or other accents. ::: ::: Current theories of sound learning (SLM, PAM) are presented and the evidence for or against is examined. A survey of experimental data leads to the conclusion that the models, whilst providing useful information and attractive approaches to explaining some learning behaviour, are insufficient, as they assume that age and experience are the only important determiners of achievement. A model is then proposed which incorporates attentional, feedback, modelling, and representational mechanisms as a framework for learner behaviour, and emphasises the learner-specific potential of these mechanisms. ::: ::: In the experimental section, a group of phonetically talented subjects imitated first language (Swedish) dialects and second languages with both immediate and delayed models. These imitations were assessed by native listeners and their accent judgements and comments are presented. It is observed that, contrary to claims in the literature, some subjects can learn to pronounce languages and dialects with no perceptible foreign accent, although there is wide variation in the data, both in terms of listener agreement, and with regard to degree of accent in the imitators’ productions. A number of observations are made regarding sound learning, the perception of accent, and the measures and norms which can reasonably be applied to learner performance and competence. <s> BIB002
The listener's task in recognising speech is in principle the same in any language; the same constraints of vocabulary makeup, the nature of speech production, and interspeaker variability apply whether the language is longknown, relatively new, or unknown. Nonetheless, there are many ways in which the broad classes of listener compared in the literature we review -native versus non-native -can vary. Comparing native and non-native performance in speech perception can be rendered difficult by the fact that the latter broad grouping may be very heterogeneous; learners in the classroom are not like strict bilinguals, etc. In this section, we examine the principal relevant dimensions of variability that can affect speech perception -listener type, first language (L1) influence, and input differences. More general reviews of issues in second language (L2) perception can be found in BIB001  BIB002   .