In this thesis I explore the phonological nature of newly acquired perceptual representations by highly proficient late-learners of English whose L1 is Spanish, specifically in the case where two different L2 sounds are being initially mapped onto the same L1 category. I claim that these perceptual representations are not phonemic; rather, what these learners acquire are phonetic representations that can be discriminable under certain conditions in a manner similar to that of native speakers, but that are nevertheless identified as tokens of the same L1 category. Since speech perception is a categorisation process where the acoustic input is mapped onto the existing phonemic categories, then late-learners will use their L1 representations when perceiving acoustic input; and will therefore have no need to create new perceptual categories. An alternative hypothesis holds that late-learners can bootstrap new perceptual categories by means of UG access, which allows them to bypass the default categorisation process and notice the difference between their L1 categories and the actual L2 input, so that new perceptual categories can be created. This thesis focuses on the acquisition of the perceptual contrast between the open-mid back unrounded vowel /2/ and the low back unrounded vowel /A/, both of which are mapped onto the same L1 perceptual category /a/. Two experiments were conducted. Subjects were divided in three groups: one of native speakers (NS), a group of highly proficient nonnative speakers of English with Spanish as L1 (NNS-A), and a group of L1 Spanish speakers who were nonproficient in English (NNS-B). The experiments included identification, discrimination and rating tasks along synthesised /A - 2/ vowel continua (7-step and 5-step). The results showed that unlike the NS group, both groups of nonnative speakers categorised the tokens along the /2 - A/ continuum randomly when using L2-like labels; and showing a strong preference towards /a/ when using L1-like labels. Discrimination, on the other hand, differed according to the task: discrimination of adjacent tokens yielded similar results across the three groups, but nonadjacent tokens showed that the NNS-A group is more sensitive than the NNS-B group and less sensitive than the NS group. Finally, prototypicality ratings showed that while NS considered the endpoints of the continuum as good exemplars of the categories /A/ and /2/, both groups of nonnative speakers rated all tokens along the continuum as equally good instances of /a/. From these results I conclude that while late-learners of L2 English do not create new phonemic categories for /A/ and /2/, they are able to perceive a difference that nevertheless does not seem to be enough to create a category split. These findings have implications for a theory of learnability in SLA, since it suggests that latelearners have partial access to UG insofar as input alone leads to learning within the phonetic domain but not to creation of new phonemic categories.

Building upon current research in native-speaker (NS) perception of L2 learner phonology (Zielinski, 2008; Derwing & Munro, 2009), the present investigation analyzed multiple dimensions of NS speech perception in order to achieve a more complete understanding of the specific linguistic elements and attitudinal variables that contribute to perceptions of accent in learner speech. In this mixed-methods study, Spanish monolinguals (n = 18) provided information regarding their views of L1 American English (AE) speakers learning Spanish and also evaluated the extemporaneous production of L2 learners from this same population. The evaluators' preconceived attitudinal notions of L1 AE speakers learning Spanish negatively correlated with numerical accentedness ratings for the speech samples, indicating that evaluators with more positive perceptions of the learners rated their speech as less accented. Following initial numerical ratings, evaluators provided detailed commentary on the individual phonological elements from each utterance that they perceived as "nonnative." Results show that differences in the relative salience of the nonnative segmental productions correspond with certain phonetic and phonemic processes occurring within the sounds, such as aspiration, spirantization and lateralization. / Spanish

It is a general belief in Japan that the English /s/ and /ʃ/ before high front vowels (as in "see" and "she") are problematic for Japanese ESL (English-as-a-second-language) learners. Some research has also reported the /s/ and /ʃ/ confusion by Japanese ESL learners. Their pronunciation errors are often explained based on phonetics, but there are reasons to believe that the learners’ knowledge of the phonemes of the target words is at fault. This study examines 1) whether monolingual Japanese speakers distinguish the [si] and [ʃi] syllables in both perception and production in the Japanese contexts and 2) what would be the sources of Japanese speakers’ challenges in mastering the distinction between [si] and [ʃi] in their English production if Japanese speakers can produce and perceive the difference between these syllables. This study conducted two experiments. In the first experiment, 93 monolingual Japanese speakers between the ages of 17 and 89 in and around Tôkyô read aloud the written stimuli that had [si] and [ʃi] in the Japanese contexts, repeated the sound stimuli that had [si] and [ʃi] in the Japanese contexts, and listened to the [si:] and [ʃi:] syllables in isolation recorded by a native speaker of Canadian English. The results showed that the participants all distinguished [si] and [ʃi] in both perception and production regardless of their ages. Based on these results, I hypothesized that the [s] and [ʃ] confusion by Japanese ESL learners is caused by misunderstanding, rather than an inability to articulate these sounds. In the second experiment, 27 Japanese ESL students were recorded reading an English passage. The passage contains /s/ (7 times) and /ʃ/ (11 times) before high front vowels. After the reading, the participants were taught the basic English phonological system and the symbol-sound correspondence rules such as “s”-/s/ and “sh”-/ʃ/. The lesson lasted 40 minutes during which the participants were also interviewed to find out their awareness of the symbol-sound correspondence. No articulation explanations were given during the lesson. After the lesson, the participants read the same passage. The results showed that /s/ and /ʃ/ were mispronounced 39 and 67 times respectively in total by the 27 participants before the lesson, but only 7 and 19 times after the lesson. These changes are statistically significant. Moreover, the interview during the lesson revealed that the participants lacked phonological awareness in English as well as the knowledge of the symbol-sound correspondence rules. This study concluded that many of the mispronunciations by Japanese ESL learners, including /s/ and /ʃ/, can be solved by teaching the English phonics rules and some basic phonological rules without teaching the articulation of these sounds.