Journal of Phonetics最新文献

This paper provides evidence for the assumption that the precise phonetic implementation of laryngeal contrast in obstruents can have an influence on higher order linguistic structure. Traditional varieties of Jutland Danish – which are all broadly ‘aspirating’ varieties – are used as a case study. The paper shows that the precise implementation of the aspirated–unaspirated contrast in stops varied systematically in these varieties, and that this covaries with the morphophonological process of stop gradation. Stop gradation is a lenition process which is historically found in the entire Danish-speaking area, but with quite varying outcomes, which were mapped extensively by dialectologists more than a century ago. Using a large legacy corpus of sociolinguistic interviews from the 1970s, this study shows that more sonorous outcomes of stop gradation covary with higher rates of continuous closure voicing in /b d g/ and shorter aspiration in /p t k/, and vice versa for less sonorous outcomes of stop gradation.

It has long been a mystery how children learn to speak without formal instructions. Previous research has used computational modelling to help solve the mystery by simulating vocal learning with direct imitation or caregiver feedback, but has encountered difficulty in overcoming the speaker normalisation problem, namely, discrepancies between children’s vocalisations and that of adults due to age-related anatomical differences. Here we show that vocal learning can be successfully simulated via recognition-guided vocal exploration without explicit speaker normalisation. We trained an articulatory synthesiser with three-dimensional vocal tract models of an adult and two child configurations of different ages to learn monosyllabic English words consisting of CVC syllables, based on coarticulatory dynamics and two kinds of auditory feedback: (i) acoustic features to simulate universal phonetic perception (or direct imitation), and (ii) a deep-learning-based speech recogniser to simulate native-language phonological perception. Native listeners were invited to evaluate the learned synthetic speech with natural speech as baseline reference. Results show that the English words trained with the speech recogniser were more intelligible than those trained with acoustic features, sometimes close to natural speech. The successful simulation of vocal learning in this study suggests that a combination of coarticulatory dynamics and native-language phonological perception may be critical also for real-life vocal production learning.

Ultrasound imaging of the tongue is biased by the probe movements relative to the speaker’s head. Two common remedies are restricting or algorithmically compensating for such movements, each with its own challenges. We describe these challenges in details and evaluate an open-source, adjustable probe stabilizer for ultrasound (ALPHUS), specifically designed to address these challenges by restricting uncorrectable probe movements while allowing for correctable ones (e.g., jaw opening) to facilitate naturalness. The stabilizer is highly modular and adaptable to different users (e.g., adults and children) and different research/clinical needs (e.g., imaging in both midsagittal and coronal orientations). The results of three experiments show that probe movement over uncorrectable degrees of freedom was negligible, while movement over correctable degrees of freedom that could be compensated through post-processing alignment was relatively large, indicating unconstrained articulation over parameters relevant for natural speech. Results also showed that probe movements as small as 5 mm or 2 degrees can neutralize phonemic contrasts in ultrasound tongue positions. This demonstrates that while stabilized but uncorrected ultrasound imaging can provide reliable tongue shape information (e.g., curvature or complexity), accurate tongue position (e.g., height or backness) with respect to vocal tract hard structure needs correction for probe displacement relative to the head.

Suzhou Wu Chinese has undergone a transphonologization of a voicing contrast in initial consonants to a tone contrast. In consequence, the tone system has split into two registers, in which the high register tones are higher in pitch and modal voiced, whilst the low register tones are lower in pitch and breathy voiced. Our previous studies have found that breathy voice in the low register tones is disappearing in younger speakers’ production. This finding motivated us to investigate the effect of breathy voice on tone identification across age groups. Participants from three age groups completed a tone identification experiment. Stimuli were constructed based on natural tokens produced by a middle-aged female speaker and an older female speaker. The manipulation of phonation was accomplished by using the base syllables of both high and low register tones, for both unchecked (T1 vs. T2) and checked (T7 vs. T8) tone pairs. The results showed that breathy voice is still used by younger listeners in their perception and its effect on their tone identification is similar to that for older and middle-aged listeners. Moreover, the effect of breathy voice is modulated by social indexical factors (i.e., talker voice). The implications of the results for the origin of the loss of breathy voice in Suzhou Wu and the mechanism of sound change are discussed.

This study explores downstepping in Mainstream US English using three experiments. Experiment 1 investigated if downstep was associated with accessible referents. Pairs of scenarios were constructed: one with new information and one with accessible. Two versions of the target utterances were recorded (one with high star, and one with downstepping) and presented in the accessible and new contexts. The high star contour was preferred overall, but less so in accessible contexts. A statistical model showed an effect of the phonetic implementation of the contour. Experiment 2 examined the phonetic realizations of the utterances in Experiment 1 using a categorical perception discrimination task. Participants showed linear perception within the downstep contours but a categorical difference between the high star and downstep contours. Experiment 3 explored the interpretations attached to downstepping. Listeners showed a categorical difference between high star and downstep contours for interpretation, hearing downstep as indicating something had happened before, and more resigned, disappointed, and less clear than high star contours. There was also variation within the downstep contours based on phonetic implementation of the contour. We show that downstep contours have distinct meanings from high star contours, and that these meanings may be mediated by their phonetic implementation.

The diachronic change by which coarticulatory nasalization increases in VN (vowel-nasal) sequences has been modelled as an earlier alignment of the velum combined with oral gesture weakening of N. The model was tested by comparing American (USE) and Standard Southern British English (BRE) based on the assumption that this diachronic change is more advanced in USE. Real-time MRI data was collected from 16 USE and 27 BRE adult speakers producing monosyllables with coda /Vn, Vnd, Vnz/. For USE, nasalization was greater in V, less in N, and there was greater tongue tip lenition than for BRE. The dialects showed a similar stability of the velum gesture and a trade-off between vowel nasalization and tongue tip lenition. Velum alignment was not earlier in USE. Instead, a closer approximation of the time of the tongue tip peak velocity towards the tongue tip maximum for USE caused a shift in the acoustic boundary within VN towards N, giving the illusion that the velum gesture has an earlier alignment in USE. It is suggested that coda reduction which targets the tongue tip more than the velum is a principal physiological mechanism responsible for the onset of diachronic vowel nasalization.

The pitch accent system of Mainstream American English (MAE) is one of the most well-studied phenomena within the Autosegmental-Metrical (AM) approach to intonation. In this work we present an explicit model grounded in dynamical theory that predicts both qualitative phonological and quantitative phonetic generalizations about the MAE system. While the traditional AM account separates a phonological model of the structure of the accents from the F0 algorithm that interprets the phonological specification, we propose a unified dynamical model that encompasses both. The proposed model is introduced incrementally, one dynamical term at a time, to arrive at the minimal model needed to account for observed empirical generalizations, avoiding unnecessary complexity. The quantitative and qualitative properties of the MAE system that inform the dynamical model are based on an analysis of a large database of productions of the four most well-studied pitch accents of American English: three rising accents (H*, L+H*, L*+H) and a low-falling accent (L*). The dynamic model highlights the importance of velocity-based measures of F0, not typically invoked in intonational research, as key to understanding F0 differences among pitch accent categories. Although the focus of this work is on the MAE pitch accent system, suggestions are made for how the unified phonetic-phonological dynamical framework presented can be further developed to account for other pitch-based phenomena in a variety of languages.

We provide a phonetic examination of intrusive vowels in Sgi Bara [jil]. These vowels are inserted in predictable places, and their quality (either [i], [ɨ], or [u]) is also predictable, so they are not considered phonemic. We demonstrate that they differ from phonemic vowels in their duration, being shorter; and in their articulation, being more peripheral; but not in their intensity. We then demonstrate how this phonetic understanding of the difference between intrusive and phonemic vowels can be used to answer phonological questions about Sgi Bara. We offer two case studies: phonologically ambiguous sequences of high vowels, and frequent two-word combinations that may be univerbating. The results confirm the existence of a distinction between intrusive and phonemic vowels.

Previous studies have examined whether speakers initiate longer utterances with higher F0. Evidence for such effects is mixed and is mostly based on point estimates of F0 at the beginning of the utterance. Moreover, it is unknown whether utterance length can influence F0 control solely at utterance onset or also during the utterance. We conducted a sentence production task to investigate how control of pitch register – F0 ceiling, floor, and span – is influenced by utterance length. Specifically, we test whether speakers adjust register both in relation to an initially planned utterance length – proactive F0 control – and in response to changes in utterance length that occur after response onset – reactive F0 control. Target sentences in the experiment had one, two, or three subject noun phrases, which were cued with visual stimuli. An experimental manipulation was tested in which some visual stimuli were delayed until after participants initiated the utterance. Evidence for both proactive and reactive control of register was observed. Participants adopted a higher register ceiling and broader span in longer utterances. Furthermore, they decreased the amount of ceiling compression upon encountering delayed stimuli. The findings suggest the presence of a mechanism in which speakers continuously estimate the remaining length of the utterance and use that information to adjust pitch register.

Phonetic reduction arises in the course of typical language production, when language users produce a less clearly articulated form of a word. An important factor that affects phonetic reduction is the predictability of the information conveyed: predictable information is reduced. This can be observed in everyday use of reference in spoken language. Specifically, first mention of a referent is more carefully articulated than subsequent mentions of the same referents, which are often phonetically reduced. Here we ask whether phonetic reduction for predictable information exists in a young sign language, and, in particular, how phonetic reduction is realized in visual languages that exploit various articulators of the body: the hands, the head, and the torso. The only natural languages that we can observe as they emerge in real time are young sign languages, and we focus on one of these in the current study: Israeli Sign Language (ISL). We use 3D motion-capture technology to measure phonetic reduction in signers of ISL by comparing the production of referring expressions synchronically, at different points during a narrative (e.g., Introduction, Reintroduction, Maintenance). Our findings show: (a) that phonetic reduction is present in a young sign language; and specifically (b) that the actions of different articulators involved in discourse are reduced, based on predictability. We consider the importance of these findings in understanding predictability in language more generally.