6 research outputs found

    Emergent optimal vowel systems

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    An interesting aspect of vowel systems is that they seem to balance between articulatory ease and auditory contrast. This tension is often proposed as the cause of the remarkable overlap between the organization of vowels in various languages. This thesis aims to integrate self-organizational, agent-based models of vowel dispersion with an existing Optimality Theoretic model of non-teleological phoneme dispersion. To this end, a computer simulation combining both approaches was developed. Simulation results show that dispersed vowel systems still emerge in the artificial language of the agents, although its predictions with respect to vowel quality are not entirely accurate. The ability of the model to account for the diachronic process of chain shifts caused by vowel splits or mergers is also explored. The results confirm that innate constraints are not needed to model vowel dispersion and that these types of simulations may be helpful in investigating synchronic and diachronic phonological phenomena. However, the model described in this thesis needs to be enriched with more levels of representation to increase its explanatory power.M.A.Includes appendix with Java cod

    Learning to perceive and recognize a second language : the L2LP model revised

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    We present a test of a revised version of the Second Language Linguistic Perception (l2LP) model, a computational model of the acquisition of second language (l2) speech perception and recognition. The model draws on phonetic, phonological, and psycholinguistic constructs to explain a number of L2 learning scenarios. However, a recent computational implementation failed to validate a theoretical proposal for a learning scenario where the L2 has less phonemic categories than the native language (L 1) along a given acoustic continuum. According to the l2LP, learners faced with this learning scenario must not only shift their old L 1 phoneme boundaries but also reduce the number of categories employed in perception. Our proposed revision to L2LP successfully accounts for this updating in the number of perceptual categories as a process driven by the meaning of lexical items, rather than by the learners' awareness of the number and type of phonemes that are relevant in their new language, as the previous version of L2LP assumed. Results of our simulations show that meaning-driven learning correctly predicts the developmental path of L2 phoneme perception seen in empirical studies. Additionally, and to contribute to a long-standing debate in psycholinguistics, we test two versions of the model, with the stages of phonemic perception and lexical recognition being either sequential or interactive. Both versions succeed in learning to recognize minimal pairs in the new L2, but make diverging predictions on learners' resulting phonological representations. In sum, the proposed revision to the L2LP model contributes to our understanding of L2 acquisition, with implications for speech processing in general

    Bilingual_Eng_BP_LexicalCorpus

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    Corpus composed by translation pairs of cognate and non cognate words from English and Brazilian Portuguese. The cognate status of the words wasdefined by a measure called Interlanguage normalized Levenshtein distances

    Beyond North American English : modelling vowel inherent spectral change in British English and Dutch

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    Theories and methods modelling vowel quality in terms of vowel inherent spectral change (VISC) have been developed and tested overwhelmingly on North American English (AE) dialects, which raises the question of their generalisability in non-AE dialects and other languages. The present paper examines VISC as an aspect of vowel quality in Standard Southern British English (SSBE) and Northern Standard Dutch (NSD). Despite markedly different VISC patterns, SSBE vowels are analysable along the same lines as in AE.While the same mostly holds for NSD, VISC is found to be more important for determining SSBE vowel quality, especially for SSBE nominal diphthongs. Additionally, a pair of NSD diphthongs presents a challenge for current theories and methods as they are acoustically similar. In line with studies on AE, theorising vowel quality in terms of VISC aids descriptions of vowels and removes the need to treat nominal monophthongs and diphthongs in different ways

    Efficient Evaluation and Learning in Multilevel Parallel Constraint Grammars

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    In multilevel parallel Optimality Theory grammars, the number of candidates (possible paths from the input to the output level) increases exponentially with the number of levels of representation. The problem with this is that with the customary strategy of listing all candidates in a tableau, the computation time for evaluation (i.e., choosing the winning candidate) and learning (i.e., reranking the constraints on the basis of language data) increases exponentially with the number of levels as well. This article proposes instead to collect the candidates in a graph in which the number of nodes and the number of connections increase only linearly with the number of levels of representation. As a result, there exist procedures for evaluation and learning that increase only linearly with the number of levels. These efficient procedures help to make multilevel parallel constraint grammars more feasible as models of human language processing. We illustrate visualization, evaluation, and learning with a toy grammar for a traditional case that has already previously been analyzed in terms of parallel evaluation, namely, French liaison
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