Acoustic Correlates of Word Stress as A Cue to Accent Strength

Due to the clear interference of their mother tongue prosody, many Czech learners produce their English with a conspicuous foreign accent. The goal of the present study is to investigate the acoustic cues that differentiate stressed and unstressed syllabic nuclei and identify individual details concerning their contribution to the specific sound of Czech English. Speech production of sixteen female non-professional Czech and British speakers was analysed with the sounds segmented on a word and phone level and with both canonical and actual stress positions manually marked. Prior to analyses the strength of the foreign accent was assessed in a perception test. Subsequently, stressed and unstressed vowels were measured with respect to their duration, amplitude, fundamental frequency and spectral slope. Our results show that, in general, Czech speakers use much less acoustic marking of stress than the British subjects. The difference is most prominent in the domains of fundamental frequency and amplitude. The Czech speakers also deviate from the canonical placement of stress, shifting it frequently to the first syllable. On the other hand, they seem to approximate the needed durational difference quite successfully. These outcomes support the concept of language interference since they correspond with the existing linguistic knowledge about Czech and English word stress. The study adds specific details concerning the extent of this interference in four acoustic dimensions

French Learners of L2 English: Intonation Boundaries and the Marking of Lexical Stress

To test my hypothesis, I collected passages of read speech by thirteen upper intermediate/advanced French learners of English along with the same passage read by ten native English speakers. Two trisyllabics carrying primary stress on the second syllable (com'puter, pro'tection) were placed in a series of intonational contexts under observation. The test-words were then extracted and submitted to native English listeners. The perceptual results show that the predicted ‘challenging’ contexts indeed caused substantial instability in the learners’ placement of lexical stress as perceived by native English listeners

The listening talker: A review of human and algorithmic context-induced modifications of speech

International audienceSpeech output technology is finding widespread application, including in scenarios where intelligibility might be compromised - at least for some listeners - by adverse conditions. Unlike most current algorithms, talkers continually adapt their speech patterns as a response to the immediate context of spoken communication, where the type of interlocutor and the environment are the dominant situational factors influencing speech production. Observations of talker behaviour can motivate the design of more robust speech output algorithms. Starting with a listener-oriented categorisation of possible goals for speech modification, this review article summarises the extensive set of behavioural findings related to human speech modification, identifies which factors appear to be beneficial, and goes on to examine previous computational attempts to improve intelligibility in noise. The review concludes by tabulating 46 speech modifications, many of which have yet to be perceptually or algorithmically evaluated. Consequently, the review provides a roadmap for future work in improving the robustness of speech output

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

Sociolinguistic Conditioning of Phonetic Category Realisation in Non-Native Speech

The realisation of phonetic categories reflects a complex relationship between individual phonetic parameters and both linguistic and extra-linguistic conditioning of language usage. The present paper investigates the effect of selected socio-linguistic variables, such as the age, the amount of language use and cultural/social distance in English used by Polish immigrants to the U.S. Individual parameters used in the realisation of the category ‘voice’ have been found to vary in their sensitivity to extra-linguistic factors: while the production of target-like values of all parameters is related to the age, it is the closure duration that is most stable in the correspondence to the age and level of language proficiency. The VOT and vowel duration, on the other hand, prove to be more sensitive to the amount of language use and attitudinal factors

Forming New Vowel Categories in Second Language Speech: The Case of Polish Learners' Production of English /I/ and /e/

The paper concentrates on formation of L2 English vowel categories in the speech of Polish learners. More specifically, it compares distribution of two English categories - /I/ and /e/ relative to neighbouring Polish vowels. 43 participants recorded Polish and English vowels in a /bVt/ context. First two formants were measured at a vowel midpoint and plotted on a vowel plane. The results reveal that while a separate /I/ category is formed fairly effectively in Polish learners pronunciation of English, a category of /e/ is almost completely subsumed by a Polish vowel /ϵ

Asymmetric discrimination of non-speech tonal analogues of vowels

Published in final edited form as: J Exp Psychol Hum Percept Perform. 2019 February ; 45(2): 285–300. doi:10.1037/xhp0000603.Directional asymmetries reveal a universal bias in vowel perception favoring extreme vocalic articulations, which lead to acoustic vowel signals with dynamic formant trajectories and well-defined spectral prominences due to the convergence of adjacent formants. The present experiments investigated whether this bias reflects speech-specific processes or general properties of spectral processing in the auditory system. Toward this end, we examined whether analogous asymmetries in perception arise with non-speech tonal analogues that approximate some of the dynamic and static spectral characteristics of naturally-produced /u/ vowels executed with more versus less extreme lip gestures. We found a qualitatively similar but weaker directional effect with two-component tones varying in both the dynamic changes and proximity of their spectral energies. In subsequent experiments, we pinned down the phenomenon using tones that varied in one or both of these two acoustic characteristics. We found comparable asymmetries with tones that differed exclusively in their spectral dynamics, and no asymmetries with tones that differed exclusively in their spectral proximity or both spectral features. We interpret these findings as evidence that dynamic spectral changes are a critical cue for eliciting asymmetries in non-speech tone perception, but that the potential contribution of general auditory processes to asymmetries in vowel perception is limited.Accepted manuscrip

A language-familiarity effect for speaker discrimination without comprehension

The influence of language familiarity upon speaker identification is well established, to such an extent that it has been argued that “Human voice recognition depends on language ability” [Perrachione TK, Del Tufo SN, Gabrieli JDE (2011) Science 333(6042):595]. However, 7-mo-old infants discriminate speakers of their mother tongue better than they do foreign speakers [Johnson EK, Westrek E, Nazzi T, Cutler A (2011) Dev Sci 14(5):1002–1011] despite their limited speech comprehension abilities, suggesting that speaker discrimination may rely on familiarity with the sound structure of one’s native language rather than the ability to comprehend speech. To test this hypothesis, we asked Chinese and English adult participants to rate speaker dissimilarity in pairs of sentences in English or Mandarin that were first time-reversed to render them unintelligible. Even in these conditions a language-familiarity effect was observed: Both Chinese and English listeners rated pairs of native-language speakers as more dissimilar than foreign-language speakers, despite their inability to understand the material. Our data indicate that the language familiarity effect is not based on comprehension but rather on familiarity with the phonology of one’s native language. This effect may stem from a mechanism analogous to the “other-race” effect in face recognition