Analyzing Prosody with Legendre Polynomial Coefficients

This investigation demonstrates the effectiveness of Legendre polynomial coefficients representing prosodic contours within the context of two different tasks: nativeness classification and sarcasm detection. By making use of accurate representations of prosodic contours to answer fundamental linguistic questions, we contribute significantly to the body of research focused on analyzing prosody in linguistics as well as modeling prosody for machine learning tasks. Using Legendre polynomial coefficient representations of prosodic contours, we answer prosodic questions about differences in prosody between native English speakers and non-native English speakers whose first language is Mandarin. We also learn more about prosodic qualities of sarcastic speech. We additionally perform machine learning classification for both tasks, (achieving an accuracy of 72.3% for nativeness classification, and achieving 81.57% for sarcasm detection). We recommend that linguists looking to analyze prosodic contours make use of Legendre polynomial coefficients modeling; the accuracy and quality of the resulting prosodic contour representations makes them highly interpretable for linguistic analysis

ESL speakers\u27 production of English lexical stress: The effect of variation in acoustic correlates on perceived intelligibility and nativeness

Non-native speakers of English often experience problems in pronunciation as they are learning English, many such problems persisting even when the speaker has achieved a high degree of fluency. Research has shown that for a non-native speaker to sound most natural and intelligible in his or her second language, the speaker must acquire proper prosody, such as native-like speech rhythms (Tajima et al., 1997; Wenk, 1985; Wennerstrom, 2001). This dissertation investigates how native English and Spanish ESL (English as a Second Language) speakers compare in their production of three acoustic correlates of lexical stress in English, namely the relative durations of stressed and unstressed vowels and their relative intensities and fundamental frequency (F0) values. A set of three-syllable words, including cognates and non-cognates, was analyzed. The results from the production study were used to design a listening task that investigated how the ESL speakers varying productions of these acoustic cues affected native English listeners\u27 perception of their speech intelligibility and nativeness. The ESL speakers produced a wider range of values than did the native speakers for all three acoustic correlates. The ESL and native speakers differed statistically in their productions of Spanish/English cognates with different stress patterns in each language and often differed on non-cognates. The ESL group produced the most native-like patterns in cognates with the same stress pattern in each language. The stimuli for the listening task were words recorded by native English participants and subsequently modified to emulate the production of the acoustic correlates of lexical stress by the ESL speakers. Listeners\u27 ratings of speech intelligibility were statistically higher for words in which intensity was increased on the vowel that is expected to receive lexical stress compared to the adjacent unstressed vowel. Increasing vowel duration on the unstressed vowel led to statistically lower ratings of both intelligibility and nativeness. This dissertation contributes to a small body of research regarding the production of prosody in second language speech. The results suggest that a speaker\u27s prosody alone can influence a native listener\u27s perception of speech intelligibility and nativeness

Segmental foreign accent

200 p.Tradicionalmente, el acento extranjero se ha estudiado desde una perspectiva holística, es decir, tratándolo como un todo en lugar de como una serie de rasgos individuales que suceden simultáneamente. Los estudios previos que se han centrado en alguno de estos rasgos individuales lo han hecho generalmente en el plano suprasegmental (Tajima et al., 1997, Munro & Derwing, 2001, Hahn, 2004, etc.). En esta tesis se lleva a cabo un análisis del acento extranjero desde un punto de vista segmental. Considerando que no existe mucha investigación en este campo, nuestro principal objetivo es averiguar si los resultados de estudios holísticos previos pueden ser extrapolados al nivel segmental. Con el objetivo de analizar el nivel segmental en detalle, en esta tesis se presentan técnicas que hacen uso de nuevas tecnologías. Para recabar la mayor información posible, los experimentos perceptivos son llevados a cabo con oyentes con muy distintos perfiles lingüísticos en términos de primera lengua o conocimiento de la segunda lengua y comparados con la literatura existente. Nuestros resultados muestran que algunos efectos importantes relativos a la producción y percepción de segmentos acentuados pueden pasar inadvertidos en un análisis holístico y acreditan la necesidad de continuar realizando estudios de unidades mínimas para comprender en profundidad los efectos del acento extranjero en la comunicación

Segmental foreign accent

200 p.Tradicionalmente, el acento extranjero se ha estudiado desde una perspectiva holística, es decir, tratándolo como un todo en lugar de como una serie de rasgos individuales que suceden simultáneamente. Los estudios previos que se han centrado en alguno de estos rasgos individuales lo han hecho generalmente en el plano suprasegmental (Tajima et al., 1997, Munro & Derwing, 2001, Hahn, 2004, etc.). En esta tesis se lleva a cabo un análisis del acento extranjero desde un punto de vista segmental. Considerando que no existe mucha investigación en este campo, nuestro principal objetivo es averiguar si los resultados de estudios holísticos previos pueden ser extrapolados al nivel segmental. Con el objetivo de analizar el nivel segmental en detalle, en esta tesis se presentan técnicas que hacen uso de nuevas tecnologías. Para recabar la mayor información posible, los experimentos perceptivos son llevados a cabo con oyentes con muy distintos perfiles lingüísticos en términos de primera lengua o conocimiento de la segunda lengua y comparados con la literatura existente. Nuestros resultados muestran que algunos efectos importantes relativos a la producción y percepción de segmentos acentuados pueden pasar inadvertidos en un análisis holístico y acreditan la necesidad de continuar realizando estudios de unidades mínimas para comprender en profundidad los efectos del acento extranjero en la comunicación

Automatic assessment of non-native prosody by measuring distances on prosodic label sequences

The aim of this paper is to investigate how automatic prosodic labeling systems contribute to the evaluation of non-native pronunciation. In particular, it examines the efficiency of a group of metrics to evaluate the prosodic competence of non-native speakers, based on the information provided by sequences of labels in the analysis of both native and non-native speech. A group of Sp ToBI labels were obtained by means of an automatic labeling system for the speech of native and non-native speakers who read the same texts. The metrics assessed the differences in the prosodic labels for both speech samples. The results showed the efficiency of the metrics to set apart both groups of speakers. Furthermore, they exhibited how nonnative speakers (American and Japanese speakers) improved their Spanish productions after doing a set of listening and repeating activities. Finally, this study also shows that the results provided by the metrics are correlated with the scores given by human evaluators on the productions of the different speaker

한국인 영어 학습자의 대조초점 발화와 외국인 억양성

학위논문 (석사)-- 서울대학교 대학원 : 외국어교육과(영어전공), 2015. 7. 안현기.본 연구는 한국 영어 교육의 중요한 목표인 의사소통능력 향상을 도모하기 위한 한 가지 방법으로 발음교육이 중요하다고 보고, 그 중에서도 표면적 의미 이상을 전달하는 기능을 하는 운율 교육의 필요성을 되새기고자 하였다. 그 중에서도 문맥과 화자의 의도에 따라 초점의 위치가 달라지는 대조 초점에 천착하여, 상급 수준의 한국인 영어 학습자들이 대조초점을 적절한 위치에 발화할 수 있는지, 또한 그들의 대조초점 발화 문장이 어느 정도 외국인 억양성이 인지되는지를 중점적으로 살펴보려 한다. 이에 따른 연구 문제는 다음과 같다. 1) 한국인 상급 영어 학습자는 대조초점을 강조되는 단어에 부과할 수 있는지 2) 한국인 상급 영어 학습자들이 대조초점을 적절한 위치에서 실현한다면 그들의 발화 상에서 외국인 억양성 정도는 어떻게 느껴지는지 3) 한국인 상급 영어 학습자 들의 영어를 처음 배운 시기가 그들의 발화 상의 외국인 억양성 정도에 영향을 주는지에 대한 연구 문제를 제시하였다. 본 실험에서는 서울 소재 대학의 상급 영어 수준을 보유하고 있는 학생 37명을 대상으로 선택의문문(alternative questions)을 이용한 대조초점 발화 실험을 하였다. 한 문장에 세 개의 선택의문문을 제시하여 질문의 내용에 따라 대조초점의 위치를 달리하여 대답할 수 있도록 유도하였다. 세 명의 영어 원어민 채점자가 참가자들의 발화 문장을 듣고 가장 돋들리는 단어를 찾은 후 문장 전체에 대한 외국인 억양성 정도를 표시하도록 지시받았다. 실험 결과, 첫째, 한국인 상급 영어학습자들은 의미상 강조되는 단어가 돋들리도록 대조초점을 실현하지 못하는 것으로 드러났다. 이는 한국인 학습자가 대조초점을 어떤 방식으로 구현해야 하는지 잘 알지 못하는 것에서 기인한 것으로 보인다. 둘째, 대조초점이 적절한 위치에 나타난 문장과 그렇지 않은 문장과의 외국인 억양성 정도를 비교하였을 때 유의미한 차이가 없는 것으로 나타났다. 이것은 청자가 외국인 억양성을 인지할 때 운율이 더 영향력 있는 요소가 아닐 수도 있다는 것을 암시한다. 셋째, 한국인 학습자의 처음 영어를 배운 나이와 외국인 억양성 정도에 차이가 있는 것으로 나타났다. 8세 이전에 영어를 배운 학습자는 그 이후에 배운 학습자들과 유의미한 차이를 보여주었다. 이것은 이민자들이 처음 해당 국가에 도착한 나이와 외국인 억양성의 관계를 살펴본 많은 연구들과 일치하는 결과로, 영어를 외국어로서 배우는 환경에도 적용될 수 있다는 것을 보여준다.ABSTRACT i TABLE OF CONTENTS iii LIST OF TABLES v LIST OF FIGURES vi CHAPTER 1. INTRODUCTION 1 1.1 The Purpose of the Study 1 1.2 Research Questions 5 1.3 Organization of the Thesis 6 CHAPTER 2. LITERATURE REVIEW 7 2.1 The Role of Prosody in Communication 8 2.1.1 The Role of Prosody in Comprehensibility and Intelligibility 8 2.1.2 The Role of Prosody in Perceived Foreign Accentedness 11 2.2 Sentence Stress and Contrastive Focus 14 2.2.1 Sentence Stress 14 2.2.2 Contrastive Focus 16 CHAPTER 3. METHODOLOGY 22 3.1 Participants 22 3.2 Research Design 25 3.2.1 Materials 25 3.2.2 Procedures 27 3.3 Data Collection and Analyses 29 3.3.1 Recording 29 3.3.2 Rating 30 3.3.3 Analyses 32 CHAPTER 4. RESULTS AND DISCUSSION 33 4.1 Advanced Korean Learners Ability to Produce Contrastive Focus 34 4.2 The Degree of Perceived Foreign Accentedness in Korean Learners Production of Contrastive Focus 42 4.3 The Effects of Onset Age of L2 on Korean Learners Production of Focal Accent and Perceived Foreign Accentedness 45 CHAPTER 5. CONCLUSION 49 5.1 Major Findings and Implications 49 5.2 Limitations and Suggestions for Further Reseach 51 REFERENCES 54 APPENDICES 61 국 문 초 록 87Maste

The Pitch Range of Italians and Americans. A Comparative Study

Linguistic experiments have investigated the nature of F0 span and level in cross-linguistic comparisons. However, only few studies have focused on the elaboration of a general-agreed methodology that may provide a unifying approach to the analysis of pitch range (Ladd, 1996; Patterson and Ladd, 1999; Daly and Warren, 2001; Bishop and Keating, 2010; Mennen et al. 2012). Pitch variation is used in different languages to convey different linguistic and paralinguistic meanings that may range from the expression of sentence modality to the marking of emotional and attitudinal nuances (Grice and Baumann, 2007). A number of factors have to be taken into consideration when determining the existence of measurable and reliable differences in pitch values. Daly and Warren (2001) demonstrated the importance of some independent variables such as language, age, body size, speaker sex (female vs. male), socio-cultural background, regional accents, speech task (read sentences vs. spontaneous dialogues), sentence type (questions vs. statements) and measure scales (Hertz, semitones, ERB etc.). Coherently with the model proposed by Mennen et al. (2012), my analysis of pitch range is based on the investigation of LTD (long-term distributional) and linguistic measures. LTD measures deal with the F0 distribution within a speaker’s contour (e.g. F0 minimum, F0 maximum, F0 mean, F0 median, standard deviation, F0 span) while linguistic measures are linked to specific targets within the contour, such as peaks and valleys (e.g. high and low landmarks) and preserve the temporal sequences of pitch contours. This investigation analyzed the characteristics of pitch range production and perception in English sentences uttered by Americans and Italians. Four experiments were conducted to examine different phenomena: i) the contrast between measures of F0 level and span in utterances produced by Americans and Italians (experiments 1-2); ii) the contrast between the pitch range produced by males and females in L1 and L2 (experiment 1); iii) the F0 patterns in different sentence types, that is, yes-no questions, wh-questions, and exclamations (experiment 2); iv) listeners’ evaluations of pitch span in terms of ±interesting, ±excited, ±credible, ±friendly ratings of different sentence types (experiments 3-4); v) the correlation between pitch span of the sentences and the evaluations given by American and Italian listeners (experiment 3); vi) the listeners’ evaluations of pitch span values in manipulated stimuli, whose F0 span was re-synthesized under three conditions: narrow span, original span, and wide span (experiment 4); vii) the different evaluations given to the sentences by male and female listeners. The results of this investigation supported the following generalizations. First, pitch span more than level was found to be a cue for non-nativeness, because L2 speakers of English used a narrower span, compared to the native norm. What is more, the experimental data in the production studies indicated that the mode of sentences was better captured by F0 span than level. Second, the Italian learners of English were influenced by their L1 and transferred L1 pitch range variation into their L2. The English sentences produced by the Italians had overall higher pitch levels and narrower pitch span than those produced by the Americans. In addition, the Italians used overall higher pitch levels when speaking Italian and lower levels when speaking English. Conversely, their pitch span was generally higher in English and lower in Italian. When comparing productions in English, the Italian females used higher F0 levels than the American females; vice versa, the Italian males showed slightly lower F0 levels than the American males. Third, there was a systematic relation between pitch span values and the listeners’ evaluations of the sentences. The two groups of listeners (the Americans and the Italians) rated the stimuli with larger pitch span as more interesting, exciting and credible than the stimuli with narrower pitch span. Thus, the listeners relied on the perceived pitch span to differentiate among the stimuli. Fourth, both the American and the Italian speakers were considered more friendly when the pitch span of their sentences was widened (wide span manipulation) and less friendly when the pitch span was narrowed (narrow span manipulation). This happened in all the stimuli regardless of the native language of the speakers (American vs. Italian)

Exploring the influence of suprasegmental features of speech on rater judgements of intelligibility

A thesis submitted to the University of Bedfordshire in partial fulfilment of the requirements for the degree of Doctor of PhilosophyThe importance of suprasegmental features of speech to pronunciation proficiency is well known, yet limited research has been undertaken to identify how raters attend to suprasegmental features in the English-language speaking test encounter. Currently, such features appear to be underrepresented in language learning frameworks and are not always satisfactorily incorporated into the analytical rating scales that are used by major language testing organisations. This thesis explores the influence of lexical stress, rhythm and intonation on rater decision making in order to provide insight into their proper place in rating scales and frameworks. Data were collected from 30 raters, half of whom were experienced professional raters and half of whom lacked rater training and a background in language learning or teaching. The raters were initially asked to score 12 test taker performances using a 9-point intelligibility scale. The performances were taken from the long turn of Cambridge English Main Suite exams and were selected on the basis of the inclusion of a range of notable suprasegmental features. Following scoring, the raters took part in a stimulated recall procedure to report the features that influenced their decisions. The resulting scores were quantitatively analysed using many-facet Rasch measurement analysis. Transcriptions of the verbal reports were analysed using qualitative methods. Finally, an integrated analysis of the quantitative and qualitative data was undertaken to develop a series of suprasegmental rating scale descriptors. The results showed that experienced raters do appear to attend to specific suprasegmental features in a reliable way, and that their decisions have a great deal in common with the way non-experienced raters regard such features. This indicates that stress, rhythm, and intonation may be somewhat underrepresented on current speaking proficiency scales and frameworks. The study concludes with the presentation of a series of suprasegmental rating scale descriptors