Effects of Phonological Contrast on Within-Category Phonetic Variation

This dissertation investigates an often assumed hypothesis in phonetics and phonology: that there should be relatively less within-category phonetic variation in production in languages which have relatively more phonological contrasts (Lindblom, 1986, on vowels). Although this hypothesis is intuitive, there is little existing evidence to support the claim and it is difficult to generalize outside of vowels. In this dissertation, I argue that this hypothesis is not trivially true and needs additional specification. I propose an extension of this hypothesis, Contrast-Dependent Variation, which predicts relative differences in extent of within-category variation between languages and individual speakers. Contrast-Dependent Variation can make predictions across multiple phonetic spaces as it considers individual phonetic dimensions to be the relevant units of comparison, rather than phonological inventory subsets (stops, vowels, etc.). Relative differences in extent of within-category variation are predicted by differences in cue weight, rather than differences in number of phonemes. The dissertation tests this hypothesis by examining two between-language case studies: stops in Hindi and English and sibilants in French and Polish. I also consider a within-language case study: individual differences in extent of within-category variation in Mandarin sibilants. The results here show that differences in extent of phonetic variability between languages and speakers are systematic; they are structured according to the system of phonological contrasts

Vowel Production in Mandarin Accented English and American English: Kinematic and Acoustic Data from the Marquette University Mandarin Accented English Corpus

Few electromagnetic articulography (EMA) datasets are publicly available, and none have focused systematically on non-native accented speech. We introduce a kinematic-acoustic database of speech from 40 (gender and dialect balanced) participants producing upper-Midwestern American English (AE) L1 or Mandarin Accented English (MAE) L2 (Beijing or Shanghai dialect base). The Marquette University EMA-MAE corpus will be released publicly to help advance research in areas such as pronunciation modeling, acoustic-articulatory inversion, L1-L2 comparisons, pronunciation error detection, and accent modification training. EMA data were collected at a 400 Hz sampling rate with synchronous audio using the NDI Wave System. Articulatory sensors were placed on the midsagittal lips, lower incisors, and tongue blade and dorsum, as well as on the lip corner and lateral tongue body. Sensors provide five degree-of-freedom measurements including three-dimensional sensor position and two-dimensional orientation (pitch and roll). In the current work we analyze kinematic and acoustic variability between L1 and L2 vowels. We address the hypothesis that MAE is characterized by larger differences in the articulation of back vowels than front vowels and smaller vowel spaces compared to AE. The current results provide a seminal comparison of the kinematics and acoustics of vowel production between MAE and AE speakers

L2-ARCTIC: A Non-Native English Speech Corpus

In this paper, we introduce L2-ARCTIC, a speech corpus of non-native English that is intended for research in voice conversion, accent conversion, and mispronunciation detection. This initial release includes recordings from ten non-native speakers of English whose first languages (L1s) are Hindi, Korean, Mandarin, Spanish, and Arabic, each L1 containing recordings from one male and one female speaker. Each speaker recorded approximately one hour of read speech from the Carnegie Mellon University ARCTIC prompts, from which we generated orthographic and forced-aligned phonetic transcriptions. In addition, we manually annotated 150 utterances per speaker to identify three types of mispronunciation errors: substitutions, deletions, and additions, making it a valuable resource not only for research in voice conversion and accent conversion but also in computer-assisted pronunciation training. The corpus is publicly accessible at https://psi.engr.tamu.edu/l2-arctic-corpus/

Is fundamental frequency a cue to aspiration in initial stops?

One production and one perception experiment were conducted to investigate the interaction of consonant voicing and fundamental frequency at the onset of voicing (onset f0) in Cantonese, a tonal language. Consonantal voicing in English can affect onset f0 up to 100 ms after voicing onset, but existing research provides inconclusive information regarding the effects of voicing on f0 in tonal languages where f0 variability is constrained by the demands of the lexical tone system. Previous research on consonantal effects on onset f0 provides two contrasting theories: These effects may be automatic, resulting from physiological constraints inherent to the speech production mechanism or they may be controlled, produced as part of a process of cue enhancement for the perception of laryngeal contrasts. Results of experiment 1 showed that consonant aspiration affects onset f0 in Cantonese only within the first 10 ms following voicing onset, comparable to results for other tonal languages. Experiment 2 showed that Cantonese listeners can use differences in onset f0 to cue perception of the voicing contrast, but the minimum extent of f0 perturbation necessary for this is greater than is found in Cantonese production, and comparable to that observed in acoustic studies of nontonal languages. These results suggest that consonantal effects on onset f0 are at least partially controlled by talkers, but that their role in the perception of voicing/aspiration may be a consequence of language independent properties of audition rather than listeners' experience with the phonological contrasts of a specific language.published_or_final_versio

Cross-language study of voicing contrasts of stop consonants in Asian languages

SIGLEAvailable from British Library Document Supply Centre- DSC:D96488 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

The Effect of Bilingual Proficiency in Indian English on Bilabial Plosive

Background: Bilingual speech production studies have highlighted that level of proficiency influences the acoustic-phonetic representation of phonemes in both languages (MacKay, Flege, Piske, & Schirru 2001; Zárate-Sández, 2015). The results for bilingual speech production reveal that proficient/early bilinguals produce distinct acoustic properties for the same phoneme in each language, whereas less proficient/late bilinguals produce acoustic properties for a phoneme that is closer to the native language (Flege et al., 2003; Fowler et al., 2008). Acoustic-phonetic studies for Hindi (L1) and Indian English (L2) for bilingual speakers have been understudied, and the level of proficiency has not been considered in Hindi and Indian English bilingual speakers. The present study aimed to measure the acoustic differences produced by bilingual speakers of varying proficiencies for Indian English on bilabial plosive and determine how the bilabial plosives are different from American English bilabial plosives. Methods: The sample size for this study was twenty-four. However, only twenty participants (eleven females) between the ages of eighteen and fifty, with normal speech and hearing, were recruited. The lack of recruitment of four more participants was due to the inability to find bilingual speakers who spoke Hindi as their first language and Indian English as their second language and COVID-19 restrictions imposed on recruitment (n=4). The participants were divided into three groups based on language and proficiency: a monolingual American English group, a proficient bilingual Hindi-Indian English group, and a less-proficient bilingual Hindi-Indian English group. The bilinguals were divided into a proficient and less proficient group based on the Language Experience and Proficiency Questionnaire (Marian, Blumenfeld, & Kaushanskaya, 2007). Following the screening, participants took part in a Nonword Repetition Task. Data were analyzed using Praat and Voice Sauce software. A linear mixed-effects model using R statistics was used for the statistical analysis. Results: Data from 20 participants (seven proficient bilingual speakers, five less-proficient bilingual speakers, and eight monolingual speakers) were included in the data analysis. Approximately four thousand repetitions were evaluated across the remaining participants. There were no significant main effects across the four dependent variables, but there was an interaction effect between group and phoneme on two dependent variables. The closure duration for proficient bilingual speakers compared to less-proficient bilingual speakers were significantly different between the voiceless unaspirated bilabial plosive (VLE) and voiceless aspirated bilabial plosive (VLH), as well as voiced unaspirated bilabial plosive (VE) and voiced aspirated bilabial plosive (VH). For spectral tilt, there was a significant difference between the VLE and VLH for proficient bilingual speakers compared to less proficient bilingual speakers. Discussion: The results of this study suggest that proficient bilingual speakers have a faster rate of speech in both their first language and second language. Therefore, it is difficult to provide information on whether this group has separate acoustic-phonetic characteristics for each phoneme for each language. In contrast, the less-proficient bilingual speakers seem to have a unidirectional relationship (i.e., first language influences the second language). Furthermore, the results of the acoustic characteristics for the control group i.e., monolingual American English speakers suggest that they may have acoustic-phonetic characteristics that represent a single acoustic-phonetic representation of bilabial plosive with their voicing contrast

A computational model for studying L1’s effect on L2 speech learning

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/ThesisDoctoral Dissertation Speech and Hearing Science 201

Barras de explosión múltiples en inglés no nativo e inglés nativo: datos provenientes de doce primeras lenguas

Voiceless plosives are frequently produced with multiple bursts (MBs), a phenomenon that has substantial implications for voice onset time measurement (VOT) of these consonants. MBs have been noted in previous research, but have not been systematically quantified. The objective of this study was to analyze MBs in non-native English (with data from twelve first languages) and native English, and to discern the effect of MBs on VOT measurement. Further, the potential effects of place of articulation (PoA), gender, speech rate, and age on MBs were explored. Results showed that VOT measurement method in the presence of MBs had a significant effect on the VOT values obtained for the plosives. In addition, MBs were influenced to a large extent by PoA, but not by gender, speech rate, or age. Comparisons between non-native English and native English revealed some significant differences, but in both varieties the analyses of MBs showed overall similar tendencies.Las oclusivas sordas se producen con frecuencia con barras de explosión múltiples, un fenómeno que tiene implicaciones sustanciales para la medición del tiempo de inicio de la sonoridad (VOT) de estas consonantes. Las barras de explosión múltiples se han observado en investigaciones anteriores, pero no se han cuantificado sistemáticamente. El objetivo de este estudio fue analizar las barras de explosión múltiples en inglés no nativo (con datos de doce idiomas como primera lengua) e inglés nativo, y discernir el efecto de las barras de explosión múltiples en la medición del tiempo de inicio de la sonoridad (VOT). Además, se exploraron los efectos potenciales del lugar de articulación (PoA), el género, la velocidad del habla y la edad en las barras de explosión múltiples. Los resultados mostraron que el método de medición de VOT en presencia de barras de explosión múltiples tuvo un efecto significativo en los valores de VOT obtenidos para las oclusivas. Además, las barras se explosión múltiples se vieron influenciadas en gran medida por el PoA, pero no por el género, la velocidad del habla o la edad. Las comparaciones entre el inglés no nativo y el inglés nativo revelaron algunas diferencias significativas, pero en ambas variedades los análisis de MB mostraron tendencias similares en general