Production and perception of tones by Dutch learners of Mandarin

The function of pitch movements varies across languages. Tone languages, such as Mandarin Chinese, use pitch configurations to differentiate between word forms. For non-tone languages (such as Dutch and English), pitch information is mainly used at the post-lexical level, e.g., to signal sentential prominence or delimit prosodic constituents. Therefore, learning to use lexical tones is always difficult for non-tone second language learners of Mandarin who are not familiar with using pitch information in a lexically contrastive way. This thesis investigates various aspects of production and perception of tones by beginning and advanced Dutch learners of Mandarin. Through a series of four experiments, this thesis examines the developmental path of Dutch learners of Mandarin at the university level in their acquisition of fine-grained tonal coarticulation patterns, distribution of attention between segments and tones, phonological processing of tones and using tonal information in spoken word recognition. The mechanisms underlying the learners’ tone acquisition are discussed with reference to current theories and models of second language acquisition and spoken word recognition. China Scholarship Council Leiden University Centre for LinguisticsTheoretical and Experimental Linguistic

THE USE OF SEGMENTATION CUES IN SECOND LANGUAGE LEARNERS OF ENGLISH

This dissertation project examined the influence of language typology on the use of segmentation cues by second language (L2) learners of English. Previous research has shown that native English speakers rely more on sentence context and lexical knowledge than segmental (i.e. phonotactics or acoustic-phonetics) or prosodic cues (e.g., word stresss) in native language (L1) segmentation. However, L2 learners may rely more on segmental and prosodic cues to identify word boundaries in L2 speech since it may require high lexical and syntactic proficiency in order to use lexical cues efficiently. The goal of this dissertation was to provide empirical evidence for the Revised Framework for L2 Segmentation (RFL2) which describes the relative importance of different levels of segmentation cues. Four experiments were carried out to test the hypotheses made by RFL2. Participants consisted of four language groups including native English speakers and L2 learners of English with Mandarin, Korean, or Spanish L1s. Experiment 1 compared the use of stress cues and lexical knowledge while Experiment 2 compared the use of phonotactic cues and lexical knowledge. Experiment 3 compared the use of phonotactic cues and semantic cues while Experiment 4 compared the use of stress cues and sentence context. Results showed that L2 learners rely more on segmental cues than lexical knowledge or semantic cues. L2 learners showed cue interaction in both lexical and sublexical levels whereas native speakers appeared to use the cues independently. In general, L2 learners appeared to have acquired sensitivity to the segmentation cues used in L2, although they still showed difficulty with specific aspects in each cue based on L1 characteristics. The results provided partial support for RFL2 in which L2 learners' use of sublexical cues was influenced by L1 typology. The current dissertation has important pedagogical implication as findings may help identify cues that can facilitate L2 speech segmentation and comprehension

Temporal articulatory stability, phonological variation, and lexical contrast preservation in diaspora Tibetan

This dissertation examines how lexical tone can be represented with articulatory gestures, and the ways a gestural perspective can inform synchronic and diachronic analysis of the phonology and phonetics of a language. Tibetan is chosen an example of a language with interacting laryngeal and tonal phonology, a history of tonogenesis and dialect diversification, and recent contact-induced realignment of the tonal and consonantal systems. Despite variation in voice onset time (VOT) and presence/absence of the lexical tone contrast, speakers retain a consistent relative timing of consonant and vowel gestures. Recent research has attempted to integrate tone into the framework of Articulatory Phonology through the addition of tone gestures. Unlike other theories of phonetics-phonology, Articulatory Phonology uniquely incorporates relative timing as a key parameter. This allows the system to represent contrasts instantiated not just in the presence or absence of gestures, but also in how gestures are timed with each other. Building on the different predictions of various timing relations, along with the historical developments in the language, hypotheses are generated and tested with acoustic and articulatory experiments. Following an overview of relevant theory, the second chapter surveys past literature on the history of sound change and present phonological diversity of Tibetic dialects. Whereas Old Tibetan lacked lexical tone, contrasted voiced and voiceless obstruents, and exhibited complex clusters, a series of overlapping sound changes have led to some modern varieties that are tone, lack clusters, and vary in the expression of voicing and aspiration. Furthermore, speakers in the Tibetan diaspora use a variety that has grown out of the contact between diverse Tibetic dialects. The state of the language and the dynamics of diaspora have created a situation ripe for sound change, including the recombination of elements from different dialects and, potentially, the loss of tone contrasts. The nature of the diaspora Tibetan is investigated through an acoustic corpus study. Recordings made in Kathmandu, Nepal, are being transcribed and forced-aligned into a useful audio corpus. Speakers in the corpus come from diverse backgrounds across and outside traditional Tibetan-speaking regions, but the analysis presented here focuses on speakers who grew up in diaspora, with a mixed input of Standard Tibetan (spyi skad) and other Tibetan varieties. Especially notable among these speakers is the high variability of voice onset time (VOT) and its interaction with tone. An analysis of this data in terms of the relative timing of oral, laryngeal, and tone gestures leads to the generation of hypotheses for testing using articulatory data. The articulatory study is conducted using electromagnetic articulography (EMA), and six Tibetan-speaking participants. The key finding is that the relative timing of consonant and vowel gestures is consistent across phonological categories and across speakers who do and do not contrast tone. This result leads to the conclusion that the relative timing of speech gestures is conserved and acquired independently. Speakers acquire and generalize a limited inventory of timing patterns, and can use timing patterns even when the conditioning environment for the development of those patterns, namely tone, has been lost

THE USE OF SEGMENTAL AND SUPRASEGMENTAL INFORMATION IN LEXICAL ACCESS: A FIRST- AND SECOND-LANGUAGE CHINESE INVESTIGATION

The present study investigated first language (L1) and second language (L2) Chinese categorization of tones and segments and use of tones and segments in lexical access. Previous research has shown that English listeners rely more on pitch height than pitch direction when perceiving lexical tones; however, it remains unclear if this superior use of pitch height aids English-speaking learners of Chinese in identifying the tones of Chinese that differ in initial pitch height. The present study aimed to investigate this issue to determine whether this pitch height advantage aids English-speaking Chinese learners in identifying the tones of Chinese by looking at the time course of categorization of Chinese tones that differed in initial pitch as well as segments. A norming study was first conducted to investigate the duration of acoustic input needed to hear tone and segment (rime) distinctions. In a gated AX discrimination task, native Chinese listeners and naïve English listeners heard increasingly large fragments of tonal pairs and segmental pairs that varied in the expected disambiguation point. The results of this norming study were used to select tonal and segmental stimulus pairs were controlled (as best as is possible) for the disambiguation timing in the next two experiments. Experiment 1 investigated the time course of categorization of tones and segments using a forced-choice gating task designed to tap into listeners’ identification of fragment categories taken from syllables that differ only in tones or only in segments. Native Chinese listeners and L1-English L2-Chinese listeners heard a single fragment of a Chinese word and identified either the tone or the rime of the heard fragment from two presented options. The results showed that the segmental contrasts had higher accuracy than tonal contrasts for both groups. The L2-Chinese listeners performed comparably to the native listeners on both tonal and segmental contrasts, and L2 Chinese listeners showed no advantage over native listeners. The second goal of this study was to investigate the time course of the use of tones and segments in lexical access. Previous work has shown that native Chinese listeners use tones and segments simultaneously in lexical access. Previous work on how second language learners of Chinese use tones in lexical access compared to segments showed that tones and segments are used at the same time; however, work in the segmental domain suggest that this should not be the case, and learners should struggle to use the new tones in online lexical access. As such, this work aimed to reinvestigate the timing of use of tones and segments in second language Chinese, as well as to compare learners’ use of tones and segments to native listeners with a highly time-sensitive measure: visual-world eye-tracking. Experiment 2 investigated the time course of use of tones and segments in online spoken word recognition for L1 and L2 groups. The same segmental and tonal pairs used in Experiment 1 were used in a visual-world eye-tracking experiment. Native Chinese listeners and L1-English L2-Chinese listeners saw two pairs of words displayed as corresponding images: one tonal pair and one segmental pair. Eye movements were recorded as participants heard a single target word in isolation and clicked on the corresponding picture. The eye movement data revealed that native Chinese listeners use tones and segments to begin constraining the lexical search at approximately the same time, and tonal information constrained the search more rapidly than did segments. The L2-Chinese learners showed segmental use comparable to that of native listeners; however, their tonal use was delayed by approximately 100 ms. In terms of speed, learners also showed more rapid use of tones in constraining the lexical search, although tones and segments were used to constrain the lexical search more slowly than they did for native listeners. These results are discussed in relation to recent L1 studies on lexical access of tones and segments and computational modeling of suprasegmental information. The results of this research is in line with previous work that showed tones and segments are used to constrain lexical access simultaneously; however, the current work does not support the conclusion that tones and segments are used in the same way, with tones constraining the lexical search faster than segments. It is suggested that the cause of this tone speed advantage is the number of competitors removed from competition when the processor is certain of a tone as opposed to certain of a segment or even rime. The present results also speak to the literature on the use of segmental and suprasegmental information in a second language and suggest that the timing of use of different cues to lexical identity is dependent on if that cue is used in the L1, since segments were processed at the same time as native speakers while tones were delayed. Speed of use seems to be independent of whether or not it is used in the L1, with both tones and segments being processed slower overall compared to native listeners

Hakka tone training for native speakers of tonal and nontonal languages

Language learning becomes increasingly difficult when novel linguistic features are introduced. Studies have shown that learners from various language backgrounds can be trained to perceive lexical tone, which assigns meaning to words using variations in pitch. In this thesis, we investigated whether native speakers of tonal Mandarin Chinese and tonal Vietnamese outperformed native speakers of nontonal English when learning Hakka Chinese tones following five sessions of tone training, and whether the complexity (i.e., density) of a listener’s native tone inventory facilitated nonnative tone learning. All groups improved in tone identification and tone word learning following training, with improvements persisting three weeks following the cessation of training. Although both tonal groups outperformed the English group in most tasks, the Mandarin group showed the most consistent advantages over the English group across tasks. Findings suggest that tone experience bolsters tone learning, but density of the tone inventory does not provide an advantage. Confusion patterns offer detailed insight of the interaction between nonnative tones and native tonal and intonational categories