This study set out to examine how correctly Mandarin speakers produced and perceived English vowels and to explore the relationship between the production and the perception of English vowels by Mandarin speakers. Fifteen native Mandarin speakers, who had lived in Canada for at least two years and received an IELTS score of 6.5 or above, participated in this study. Fifteen native speakers of Canadian English living in Vancouver at the time of the study also participated as a control group. Two experiments were conducted involving 10 English vowels: /i/, /ɪ/, /ɛ/, /æ/, /ʊ/, /u/, /ʊ/, /ɔ/, /o/, and /ʌ/. In Experiment 1, both the Mandarin speakers and the native English speakers were recorded producing the ten vowels in a /bVt/ syllable in a carrier sentence. The vowels in the recordings were then identified by four native English listeners. In Experiment 2, the Mandarin speakers did an identification test of the vowels produced by the English speakers in Experiment 1. The results showed that Mandarin speakers in this study were able to produce and perceive certain English vowels correctly, but not all of them. The results also indicated that the relationship between the production and perception of English vowels by Mandarin speakers cannot be interpreted in a straightforward way, and that that L2 experience, in terms of length of residence, age of arrival, years of learning, and age when ESL learning starts, might also play an important role in the production and perception of English vowels by Mandarin speakers. / Graduate

<div>Voice Onset Time (VOT) and onset f0 are known correlates of voicing distinctions in stops and both contribute to the production and perception of voicing (House & Fairbanks, 1953; Abramson & Lisker, 1965; Ohde, 1984). As the values of VOT and onset f0, which correspond to voicing categories, vary cross-linguistically, a second language (L2) learner has to acquire a novel use of these acoustic cues to produce and perceive voicing in their L2. Although the acquisition of the primary voicing cue, VOT, has been studied extensively in L2 research (Flege & Eefting, 1988; Flege 1991; Birdsong et al. 2007), little is known about the acquisition of onset f0. The present study compares the use of VOT and onset f0 in French and English speech produced by American learners of French (23). The study also examines evidence for phonetic drift in L2 learners by comparing their English productions to a monolingual control group (33). Results indicate that although learners’ VOT values in French were heavily influenced by English, their onset f0 production in both English and French were on target, showing that learners are able to manipulate the two cues independently of one another. Little evidence of the effect of learners’ second language on the first language was found.</div><div>This study also examines the role of individual learning history on the realization of VOT and onset f0, determining that average number of hours speaking French and age of L2 acquisition (AOA) reported by learners shows the strongest correlation with the learner’s acoustic productions.</div>

The present study adopts an acoustic approach to analyze Mandarin Chinese speakers’ production of English and Mandarin alveolar and velar nasal codas /n, ŋ/ in different preceding vowel contexts. Its purposes are to explore the interrelationship between nasal codas and the preceding vowels in both L1 (First Language) and L2 (Second language) production and to identify and explain similarities and differences between the L1 and L2 production. Specifically, 20 native Mandarin Chinese speakers performed a word-list reading task involving 22 English and Mandarin test words with three types of rimes, VN (Vn or Vŋ, i.e., a monophthong vowel followed by /n/ or /ŋ/), VGn (a diphthong vowel followed by /n/), and VG (a diphthong vowel). In total, 88 tokens (22 words x 4 repetitions) were collected for each speaker, and all tokens were measured by using the phonetic software, Praat. First, mean F1-F0 and F3-F2 (differences between the first and fundamental formant frequencies and between the third and second formant frequencies) over the first and the second half of vowel duration were measured to estimate vowel height/backness changes over the duration. Also, N1/N2/N3 (the first, second, and third nasal formants) at the midpoint of nasal murmur duration and the band energy difference (∆dB) between 0-525 Hz and 525-1265Hz bands over the nasal murmur duration were calculated to predict the alveolar or velar nasal place. Last, the vowel and nasal murmur duration (V_D & N_D) in each token were used to indicate the degree of vowel-nasal coupling. Two-tailed paired-wise t-tests and repeated measures one-way ANOVA tests were used to examine the statistical significance of the above acoustic measurements across test words. The main results show that there is a strong vowel-nasal coarticulation effect in Mandarin VN and English VGn production but not in English VN production; specifically, nasal place in Mandarin VN and English VGn rimes covaries with vowel quality change over the duration. In contrast, there is a significant durational difference among English VN rimes but not among Mandarin VN and English VGn rimes; specifically, Vŋ rimes are longer than Vn rimes in English. The strong vowel-nasal coarticulation effect in the Mandarin VN and English VGn production and the significant durational difference in the English VN production can be both related to rhythmic factors.

The productions of adult second language (L2) learners are often detected as having a foreign accent by native speakers of the target language. However, there is no clear answer for what kind of problems contribute to L2 learners’ foreign accent. This thesis aims to investigate potential factors behind foreign accent. We intend to achieve this goal by examining cross-linguistic empirical evidence of the L2 acquisition of Japanese lexical pitch accent by English learners. L2 prosody has been found to significantly influence native speakers’ auditory impression of foreign accent. L2 prosody also allows us to test crosslinguistic differences in the function of the key acoustic correlates of L2 contrasts. In this thesis we examine F0, which signals both lexical pitch accent and phrasal distinctions in Japanese, but which signals only phrasal distinctions, not lexical distinctions, in English. For adult L2 learners to achieve target-like productions, the literature suggests that three abilities are the key factors: 1) learners’ ability to differentiate the acoustic correlate of the target L2 contrasts, 2) ability to articulate the acoustic correlate of the target L2 contrasts and 3) ability to categorize the target L2 contrasts. This thesis evaluates all three of these potential factors. The main contribution of this thesis is to provide a comprehensive view of foreign accent, by investigating possible interactions between the factors and by examining the different abilities of the same learners. Another contribution is to provide empirical evidence for the nature of learners’ problems with foreign accent during L2 acquisition, by testing two groups of English learners of Japanese (experienced and inexperienced) in comparison with Japanese native speakers. The first experiment used intelligibility scores and overall F0 patterns to quantify the degree of foreign accent in the learners’ productions of Japanese lexical pitch accent. The second experiment showed that the learners’ ability to differentiate F0 contours in a nonspeech context was equal to that of the native speakers. The third experiment showed that the learners’ ability to articulate the F0 contours in a non-speech context differed from that of the native speakers. The fourth experiment showed that although learners were able to hear the phonetic differences between the target L2 contrasts, due to poor formation of the target L2 categories and poor lexical assignment ability, the inexperienced learners seem to have greater difficulty than experienced learners both in categorizing boundary items into the target L2 categories and in assigning the L2 categories to lexical items. Overall, the foreign accent of adult L2 learners’ productions is explained through a combination of articulation and categorization factors. Importantly, this cross-sectional study has indicated how learners’ problems with foreign accent change as they gain L2 experience. Whereas experienced learners seem to have problems mainly in the articulation and phonetic realization of the L2 contrasts, the inexperienced learners seem to have mainly problems in phonetic and lexical-phonological representations of the target L2 categories in addition to articulation and phonetic realization. This study offers both theoretical insights for the field of L2 speech acquisition research and also practical insights for the L2 classroom.

abstract: Much evidence has shown that first language (L1) plays an important role in the formation of L2 phonological system during second language (L2) learning process. This combines with the fact that different L1s have distinct phonological patterns to indicate the diverse L2 speech learning outcomes for speakers from different L1 backgrounds. This dissertation hypothesizes that phonological distances between accented speech and speakers' L1 speech are also correlated with perceived accentedness, and the correlations are negative for some phonological properties. Moreover, contrastive phonological distinctions between L1s and L2 will manifest themselves in the accented speech produced by speaker from these L1s. To test the hypotheses, this study comes up with a computational model to analyze the accented speech properties in both segmental (short-term speech measurements on short-segment or phoneme level) and suprasegmental (long-term speech measurements on word, long-segment, or sentence level) feature space. The benefit of using a computational model is that it enables quantitative analysis of L1's effect on accent in terms of different phonological properties. The core parts of this computational model are feature extraction schemes to extract pronunciation and prosody representation of accented speech based on existing techniques in speech processing field. Correlation analysis on both segmental and suprasegmental feature space is conducted to look into the relationship between acoustic measurements related to L1s and perceived accentedness across several L1s. Multiple regression analysis is employed to investigate how the L1's effect impacts the perception of foreign accent, and how accented speech produced by speakers from different L1s behaves distinctly on segmental and suprasegmental feature spaces. Results unveil the potential application of the methodology in this study to provide quantitative analysis of accented speech, and extend current studies in L2 speech learning theory to large scale. Practically, this study further shows that the computational model proposed in this study can benefit automatic accentedness evaluation system by adding features related to speakers' L1s. / Dissertation/Thesis / Doctoral Dissertation Speech and Hearing Science 2018

The aim of this study is to investigate whether blind individuals display cognitive advantages over sighted individuals with regard to second language acquisition. Previous studies from neuropsychology have indicated that this is the case. It has been found that blind L1 speakers can compensate for loss of vision by developing better perceptual and cognitive skills compared to sighted individuals, skills that are highly relevant to language acquisition. These studies do not, however, investigate blind L2 speakers, for whom it is not clear whether these advantages are also found.  In all, 80 adults participated in the study: 40 L2 speakers of Swedish (11 early blind, 9 late blind, 20 sighted, AO&lt;18) and a matching group and subgroups of L1 speakers. These speakers underwent tests on speech perception in noise, accentedness in an L2 and memory functions. The results revealed that L2 speakers are at a great disadvantage perceiving speech in noise compared to L1 speakers, and that there was no advantage associated with blindness. In the L1 speakers group, however, the results revealed that the early blind had advantages compared to the late blind and sighted in white noise, but that both blind groups were more negatively affected by babble noise than the sighted. The results in relation to accentedness in an L2 revealed that there were no advantages associated with blindness. The results further revealed there were no advantages associated with blindness on the episodic memory test. The results did, however, reveal that the early blind performed significantly better than the late blind and sighted on all phonological short-term memory tests and that both the early and late blind were significantly better than the sighted on recognition memory for new words, irrespective of language background. The conclusion is that blindness is associated with advantages in, for example, ability to learn new words and syntax, acquisition rate, ultimate L2 attainment, and language aptitude.

Second language learners of English often experience difficulties in English lexical stress perception. This has traditionally been attributed to transfer of prosodic unit or settings from their first language (L1). Similarly, the problem of Chinese learners with English stress perception was assumed to arise from tonal transfer. However, little research has been devoted to the investigation of the phonetic details of second language (L2) stress perception. The present research focuses on the perception of English lexical stress by Chinese learners of English. The purpose of this study is to reveal the use of acoustic cues in stress perception by Chinese learners of English. In the experiment, F0, duration and intensity were manipulated, each with five steps, on three disyllabic nonsense words to result in a total of 375 nonsense tokens. A group of native speakers of English (NE) and a group of Chinese learners of English (CE) participated in the study and judged whether the stress was on the first or second syllable in the test stimuli. The responses of Chinese learners of English in stress judgment were compared against the baseline of native English speakers. The statistical tests of reliance measures and logistic regression models were used in data analysis. Results indicated that, similar to NE participants, performance by CE participants showed systematic variation as a result of the manipulation of the three acoustic cues. However, CEs were different from NEs in their reliance on the three cues. CE had significantly lower duration and intensity reliance scores but significantly higher F0 than NE. In logistic regression analysis, compared to the NE group, F0 contributed most to the CE models, while the contribution of duration and intensity was minimal. It is concluded from this study that while all three cues have significant effects on stress perception for native English speakers, only F0 has a decisive effect on stress judgments by Chinese learners of English. This study reveals that, rather than transfer of tone at the phonological level, there is transfer of reliance on F0 in the acquisition of L2 English stress. It is suggested that the investigation of phonetic details of learners’ problems with L2 stress acquisition is necessary for L2 speech learning theories and also for L2 stress teaching.