Journal of Phonetics最新文献

Sensorimotor synchronization as a means of studying rhythmic perception-action coupling has been extensively researched across a large number of temporally regular structures including music while little is known about synchronization with speech. The present study fills this gap by applying a sensorimotor synchronization paradigm to natural speech and studying acoustic landmarks that may serve as perceptual anchors of rhythmic movement in spoken sentences. Five rhythmically relevant types of acoustic landmarks were identified in twenty sentences of English containing syllables with vocalic and non-vocalic nuclei. The landmarks were either manually defined or algorithm-generated and included nucleus onsets, peaks and onsets of inter-syllabic and inter-stress timescales, moments of the fastest energy change (approximating the P-center location), and timepoints of combined pitch and periodic power. Sensorimotor synchronization data from 32 native English participants were examined with regards to the location of an increased synchronization activity in the proximity of the predefined landmarks. The results demonstrated that participants synchronized with syllable-size units regardless of the type of syllable nucleus (vowel or consonant) and that their taps were consistently timed close to nucleus onsets. Hereby, the manually defined nucleus onsets predicted synchronization peaks as well as the algorithm-generated moments of the fastest energy change around nucleus onsets (i.e., a model of the P-center location) did. In contrast, other landmarks did not constitute a stable acoustic anchor of sensorimotor synchronization with English speech. The synchronization performance was not influenced by either acoustic F0-information or by phonological tune specifications. These findings provide new evidence for the proposals that rhythmic attention in natural speech may be locked on to fast spectral changes within a syllable as the smallest structuring unit of prosodic hierarchy.

Talker variability has been reported to facilitate generalization and retention of speech learning, but is also shown to place demands on cognitive resources. Our recent study provided evidence that phonetically-irrelevant acoustic variability in single-talker (ST) speech is sufficient to induce equivalent amounts of learning to the use of multiple-talker (MT) training. This study is a follow-up contrasting MT versus ST training with varying degrees of temporal exaggeration to examine how cognitive measures of individual learners may influence the role of input variability in immediate learning and long-term retention. Native Chinese-speaking adults were trained on the English /i/-/ɪ/ contrast. We assessed the trainees’ working memory and inhibition control before training. The two trained groups showed comparable long-term retention of training effects in terms of word identification performance and more native-like cue weighting in both perception and production regardless of talker variability condition. The results demonstrate the role of phonetically-irrelevant variability in robust speech learning and modulatory functions of nonlinguistic domain-general inhibitory control and working memory, highlighting the necessity to consider the interaction between input characteristics, task difficulty, and individual differences in cognitive abilities in assessing learning outcomes.

Learning sound categories is central to language acquisition – but we know little about the extent of phonetic variability in the learner’s input. In this study, we phonetically annotated coronal segments (/t/, /d/, /s/, /z/, and /n/) in a corpus of naturalistic American English infant-directed speech (IDS). We did not find evidence that IDS is consistently more canonical than adult-directed speech (ADS), challenging the notion of IDS as a learning register. While IDS is not more canonical than ADS overall, the canonical form was nonetheless the most frequent form in IDS for all segments except /t/. We also considered how infants may move beyond the task of identifying the canonical form to how they may learn to cluster allophones; for this purpose, we quantified the dissimilarity in the phonological environments of the variants in question. Lastly, we investigated a case in which the overwhelming majority of instantiations were not canonical – word-final t and d – and demonstrated that morphologically-conditioned suffixes were more canonical than other word final segments. This corpus is a vital step towards understanding how infants can learn to categorize sounds from their input and will be an invaluable tool for future sociolinguistic, computational and theoretical modeling of language learning.

This paper reports a developmental production-perception study of the three-way Polish sibilant contrast /s, ʂ, ɕ/ in typically developing children (N = 76). Children aged 2;11–7;11 produced words with sibilants in word-medial and initial position. They then identified the same words they produced, and the words as produced by an unknown adult female. Results show higher identification accuracy for adult productions across all ages. Production and perception data suggest that the alveolo-palatal /ɕ/ is acquired first, and that it is differentiated mainly by formant patterns. In the perceptual discrimination task, most errors were found for child-produced /ʂ/, and this persisted into the oldest ages. Early acquisition of /ɕ/ has been observed in other languages and may reflect motoric considerations as well as a focus on formant information in child speech perception. Cue weighting appears to change over age in sibilant-specific ways. While all children weight formants highest for /ɕ/, spectral cues appear to be more important for /s/ and /ʂ/, and reliance on formants may decrease with age. This work contributes to the study of cross-language differences in acquisition, provides an acoustic characterization of child-produced Polish sibilants, and elucidates the acoustic characteristics that children use in perceptual judgments of sibilants.

In the first decades of the 21st century, exemplar theory has fueled an explosion of theoretical and empirical work in speech production. We review the foundations for this framework in linguistics and cognitive science, and examine how recent empirical findings challenge core principles of exemplar theory. While theoretical advances in hybrid exemplar models address some of these issues, accounting for the emergence of structure, the incorporation of structure into exemplar updating, and the non-uniformity of phonetic variation and convergence (among other phenomena), remain major challenges for current models. We discuss future directions for developing exemplar theories as comprehensive accounts of speech production.

Geographic mobility can lead to the acquisition of new regional dialect features. This second dialect acquisition is highly variable across individuals and is affected by a range of linguistic and social factors. The realization of dialect-specific features is also affected by linguistic variables related to phonetic reduction, but this interaction has been primarily examined with a mix of mobile and non-mobile participants. In the current study, second dialect acquisition by Midwestern American young adults and its interaction with phonetic reduction processes was examined. Relative to lifetime residents of the Northern and Midland regions of American English, some Northern transplants to the Midland region exhibited second dialect acquisition and others exhibited maintenance of Northern dialect features. All talkers showed phonetic reduction due to lexical frequency, phonological neighborhood density, discourse mention, semantic predictability, and speaking style. These phonetic reduction processes only weakly interacted with dialect variation, such that less phonetic reduction was observed overall when it was potentially in conflict with dialect-specific vowel features. Taken together, the results provide additional evidence for substantial individual variation in second dialect acquisition, but limited evidence of an effect of second dialect acquisition on the interaction between dialect variation and phonetic reduction processes.