Ultrasound Tongue Imaging

This study has two purposes. The first is that of implementing a system for the processing of multi-level speech data, which allows the synchronized acquisition and processing of elect-ropalatographic, ultrasound tongue imaging and acoustic data. The second is that of testing the multi-level speech data system on a subset of Italian CV and VC sequences to ascertain how intersegmental coordination and coarticulation are related. We analyse onset-nucleus and nucleus-coda temporal relationships for three different consonants (/s/, /l/ and /k/) adjacent to either /a/ or /i/. Based on multi-level phonetic data on constriction location and overall tongue configuration, we show that the three consonants have different coarticula-tion properties and that these properties may in part explain the differences observed in the domain of temporal coordination between the consonant and the vocalic nucleus.

The diachronic process of /u/-fronting has been well-reported in Englishes worldwide, particularly in UK dialects. Phonetic studies generally quantify /u/-fronting with acoustic data referring to the second formant, which is known to be an acoustic correlate of tongue position. /u/-fronting is thus defined as a process in which the historically high back rounded vowel is articulated at the front of the mouth, resulting in higher F2 values. However, other articulatory configurations may give way to increases in F2. A reduction in lip rounding could possibly produce a similar acoustic output without necessarily requiring a fronting of the tongue. If, however, the tongue is positioned more front than back and is accompanied by lip rounding, we would expect /u/ to resemble a high front rounded vowel, such as French /y/. We test this hypothesis using production data from five British English speakers and perception data from 12 French listeners. Assuming that French /y/ and /u/ are prototypical front and back vowels, asking French listeners to classify English /u/ as either /y/ or /u/ should indicate where the English vowel stands in terms of backness. If /u/-fronting is present and French listeners perceive /y/ rather than /u/, we may question the appropriateness of the label /u/ as a phonological category of English. We conclude by asking more generally how phonetically accurate phonological labels should be and whether diachronic phonetic change requires phonological formalisation.

This study classifies the tongue shapes of the Mandarin rhotic suffix with Ultrasound Tongue Imaging (UTI), compared to American English. Our results indicate that contrary to previous descriptions, the Mandarin rhotic suffix is not always retroflex and shares many articulatory characteristics of English postvocalic /r/. Acoustic results show the rhotic has a significant effect on the preceding vowel. UTI data exhibited very little variation regardless of neighbouring vowels, suggesting the suffix is resistant to coarticulation.

Articulatory variation of /r/ has been widely observed in rhotic varieties of English, particularly with regards to tongue body shapes, which range from retroflex to bunched. However, little is known about the production of /r/ in modern non-rhotic varieties, particularly in Anglo-English. Although it is generally agreed that /r/ may be accompanied by lip protrusion, it is unclear whether there is a relationship between tongue shape and the accompanying degree of protrusion. We present acoustic and articulatory data (via ultrasound tongue imaging and lip videos) from Anglo-English /r/ produced in both hyper-and non-hyperarticulated speech. Hyperarticulation was elicited by engaging speakers in error resolution with a simulated "silent speech" recognition programme. Our analysis indicates that hyperarticulated /r/ induces more lip protrusion than non-hyperarticulated /r/. However, bunched /r/ variants present more protrusion than retroflex variants, regardless of hyperar-ticulation. Despite some methodological limitations, the use of Deep Neural Networks seems to confirm these results. An articulatory trading relation between tongue shape and accompanying lip protrusion is proposed.

Cet article évalue le potentiel d'un écarteur de lèvres pour les études phonétiques sur la perturbation. Cet appareil est désormais utilisé dans le « défi de l'écarteur de bouche » qui est devenu un véritable phénomène internet. Lors du port de l'appareil, les mouvements des lèvres sont rendus impossibles. Les données acoustiques et articulatoires de quatre locuteurs d'anglais britannique sont présentées. Un accéléromètre est utilisé pour évaluer la dynamique de la mâchoire et l'échographie linguale nous donne les informations sur les éventuelles stratégies de compensation, notamment pour la voyelle /u/. Grâce aux données échographiques, nous observons une rétraction de la langue pour /u/ perturbé, ce qui ne figure pas dans les données acoustiques correspondantes. Cette étude souligne donc les limitations d'une analyse purement acoustique de la parole perturbée. Malgré ses inconvénients, nous concluons que l'utilisation d'un écarteur de lèvres est une technique prometteuse pour la recherche sur la perturbation labiale.

"Speech without lips: an acoustic and articulatory study": This paper studies the use of a lip retractor as a potential technique for phonetic studies involving perturbation. This device is currently used by participants of the internet sensation, the so-called " no lips " or " mouth guard " challenge. Wearing the device restricts the use of the lips during speech. We present acoustic and articulatory data from four speakers of British English. Accelerometer data is used to assess the dynamics of the jaw and ultrasound tongue imaging gives us insights into potential compensation strategies, specifically for the /u/ (GOOSE) vowel. Ultrasound data revealed that three speakers showed signs of tongue retraction for perturbed /u/, which was not reflected in the corresponding acoustic data. This study highlights the limitations of a purely acoustic analysis of the effects of perturbation on speech. Despite certain limitations, we conclude that the use of the lip retractor is a promising technique for future lip perturbation studies.

This paper describes a system for the acquisition, real-time synchronization and analysis of acoustic, electropalatographic (EPG) and ultrasonographic (UTI) data.
Simultaneous data on linguo-palatal contact and tongue sagittal profiles are captured for rhotic consonants produced by a native speaker of Italian. Three anterior variants of /r/ ([ɾ], [ɹ̝] and [ɹ]) are shown to be realized with an apical tongue gesture, but different vowel-related coarticulation patterns. The paper discusses the implication of the proposed analysis for a coherent investigation of lingual and linguo-palatal dynamics.

We investigate lingual articulation in alveolar stops produced by 5 native Tuscan Italian speakers and varying for voicing and phonological length. Both constriction location and overall tongue configuration are evaluated. The results suggest uniformity in constriction location of singleton and geminate stops as well as in voiced and voiceless stops. On the contrary, overall tongue configuration shows different patterns for length and voicing. Moreover, the subjects show individual preferences as far as constriction location is concerned. The findings are discussed with reference to cross-linguistic patterns of articulatory variation as a function of changes in duration and glottal activity associated to the production of alveolar stops.

Tahltan is an Athapaskan language with perhaps the world's only three-way consonant harmony system (dental, alveolar, and alveopalatal). Although most explanations have depended on feature analysis, Gafos [1] proposed that differences in tongue grooving could account for the pattern. Here, we use ultrasound to examine the initial plausibility of this argument by determining whether a language without consonant harmony, American English, also shows such groove patterns. Finding such a pattern would support its possible existence in the precursors to Tahltan, from which the harmony system could arise. Coronal sections of the anterior portion of the tongue of three speakers of English uttering CVC syllables were collected via ultrasound and the depths of the groove measured. The data are consistent with Gafos's predictions, with three groove depths differing for the three classes of consonants. This pattern supports the possibility that the consonant harmony derives from this ancillary feature of consonant production.

Most varieties of English distinguish two allophones for /l/: a clear variant in onset, and a dark one in coda. French, however, has one clear allophone in all contexts . Articulatory data has shown that English coda /l/ is produced with a retraction and lowering of the tongue body . English /r/ is generally divided into two broad categories, retroflex [ɻ] or bunched [ɹ], which, unlike /l/ allophones, have been shown not to make a perceptible difference to native listeners . /r/ exhibits therefore a "many-to-one articulatory-acoustic relationship" . The French rhotic consonant, the uvular fricative [ʁ], is dissimilar in both acoustic and articulatory terms. Previous research has revealed that French learners struggle to differentiate English /r/ from /w/. A purely phonological modelling of the perception of non-native contrasts cannot account for such a finding. Language-specific phonetic similarities may then also play a role. We predicted that at an articulatory-phonetic level, French learners would not produce English liquids in the same way as native speakers. To help French learners acquire the complex articulatory gestures for these sounds, we propose an articulatory training session using ultrasound tongue imaging (UTI) and video of the lips as visual biofeedback. If the source of perceptual constraints lies in surface-level articulatory phonetics, an improvement in production should result in an improvement in perception of these contrasts.