Coarticulatory Patterns Research Articles

Effects of Word Position on the Acoustic Realization of Vietnamese Final Consonants

A variety of studies have shown differences between phonetic features of consonants according to their prosodic and/or syllable (onset vs. coda) positions. However, differences are not always found, and interactions between the various factors involved are complex and not well understood. Our study compares acoustical characteristics of coda consonants in Vietnamese taking into account their position within words. Traditionally described as monosyllabic, Vietnamese is partially polysyllabic at the lexical level. In this language, tautosyllabic consonant sequences are prohibited, and adjacent consonants are only found at syllable boundaries either within polysyllabic words (CVC.CVC) or across monosyllabic words (CVC#CVC). This study is designed to examine whether or not syllable boundary types (interword vs. intraword) have an effect on the acoustic realization of codas. The results show significant acoustic differences in consonant realizations according to syllable boundary type, suggesting different coarticulation patterns between nuclei and codas. In addition, as Vietnamese voiceless stops are generally unreleased in coda position, with no burst to carry consonantal information, our results show that a vowel's second half contains acoustic cues which are available to aid in the discrimination of place of articulation of the vowel's following consonant.

An Ultrasound Study of the Development of Lingual Coarticulation during Childhood

Background/Aims: There is growing evidence that coarticulation development is protracted and segment-specific, and yet very little information is available on the changes in the extent of coarticulation across different phonemes throughout childhood. This study describes lingual coarticulatory patterns in 6 age groups of Scottish English-speaking children between 3 and 13 years old. Methods: Vowelon-consonant anticipatory coarticulation was analysed using ultrasound imaging data on tongue shape from 4 consonants that differ in the degree of constraint, i.e., the extent of articulatory demand, on the tongue. Results: Consonant-specific age-related patterns are reported, with consonants that have more demands on the tongue reaching adolescent-like levels of coarticulation in older age groups. Within-speaker variability in tongue shape decreases with increasing age. Conclusion: Reduced coarticulation in the youngest age group may be due to insufficient tongue differentiation. Immature patterns for lingual consonants in 5- to 11-year-olds are explained by the goal of producing the consonant target overriding the goal of coarticulating the consonant with the following vowel.

Specificity for coarticulatory vowel nasality in lexical representations.

Surface-level phonetic details are used during word recognition. Yet, questions remain about how these details are encoded in lexical representations and the role of memory and attention during this process. The current study utilizes lexical repetition priming to examine the effect of a delay between hearing a word repeated with either the same or different coarticulatory patterns on lexical recognition. Listeners were faster to recognize repeated words with the same patterns of coarticulatory nasality, confirming that subphonemic information is encoded in the lexicon. Furthermore, when listeners had to adapt to more than one talker, greater coarticulatory specificity in delayed priming was observed suggesting that word-specific encoding of subphonemic details is an active cognitive process.

Fricative Contrast and Coarticulation in Children With and Without Speech Sound Disorders.

The purpose of this study was, first, to expand our understanding of typical speech development regarding segmental contrast and anticipatory coarticulation, and second, to explore the potential diagnostic utility of acoustic measures of fricative contrast and anticipatory coarticulation in children with speech sound disorders (SSD). In a cross-sectional design, 10 adults, 17 typically developing children, and 11 children with SSD repeated carrier phrases with novel words with fricatives (/s/, /ʃ/). Dependent measures were 2 ratios derived from spectral mean, obtained from perceptually accurate tokens. Group analyses compared adults and typically developing children; individual children with SSD were compared to their respective typically developing peers. Typically developing children demonstrated smaller fricative acoustic contrast than adults but similar coarticulatory patterns. Three children with SSD showed smaller fricative acoustic contrast than their typically developing peers, and 2 children showed abnormal coarticulation. The 2 children with abnormal coarticulation both had a clinical diagnosis of childhood apraxia of speech; no clear pattern was evident regarding SSD subtype for smaller fricative contrast. Children have not reached adult-like speech motor control for fricative production by age 10 even when fricatives are perceptually accurate. Present findings also suggest that abnormal coarticulation but not reduced fricative contrast is SSD-subtype-specific. S1: https://doi.org/10.23641/asha.5103070. S2 and S3: https://doi.org/10.23641/asha.5106508.

Spectral Coefficient Analyses of Word-Initial Stop Consonant Productions Suggest Similar Anticipatory Coarticulation for Stuttering and Nonstuttering Adults.

A longstanding hypothesis about the sensorimotor mechanisms underlying stuttering suggests that stuttered speech dysfluencies result from a lack of coarticulation. Formant-based measures of either the stuttered or fluent speech of children and adults who stutter have generally failed to obtain compelling evidence in support of the hypothesis that these individuals differ in the timing or degree of coarticulation. Here, we used a sensitive acoustic technique-spectral coefficient analyses-that allowed us to compare stuttering and nonstuttering speakers with regard to vowel-dependent anticipatory influences as early as the onset burst of a preceding voiceless stop consonant. Eight adults who stutter and eight matched adults who do not stutter produced C1VC2 words, and the first four spectral coefficients were calculated for one analysis window centered on the burst of C1 and two subsequent windows covering the beginning of the aspiration phase. Findings confirmed that the combined use of four spectral coefficients is an effective method for detecting the anticipatory influence of a vowel on the initial burst of a preceding voiceless stop consonant. However, the observed patterns of anticipatory coarticulation showed no statistically significant differences, or trends toward such differences, between the stuttering and nonstuttering groups. Combining the present results for fluent speech in one given phonetic context with prior findings from both stuttered and fluent speech in a variety of other contexts, we conclude that there is currently no support for the hypothesis that the fluent speech of individuals who stutter is characterized by limited coarticulation.

Öhman returns: New horizons in the collection and analysis of imaging data in speech production research

There have been enormous technical advances in the use of imaging techniques in speech production research in terms of resolution and frame rates. However, a major bottleneck lies in the lack of appropriate data reduction and quantification methods which allow for a parsimonious representation of the high-dimensional image data. Particularly the rapid increase in frame rates seen in data acquisition makes traditional, error-prone methods of contour tracking unwieldy due to the high amount of manual intervention required. We discuss recent developments in methods that obviate contour tracking but instead process the entire image. Specifically, we focus on one such approach by demonstrating the application of Principal Component Analysis to ultrasound images. This method not only exploits the information present in the entire image, but it also straightforwardly allows for the representation of the temporal evolution of an utterance by reducing a series of images to a time-varying single-value representation. In an illustrative example, inspired by the seminal work of Öhman (1966), we show how characteristic patterns of coarticulation between vowels and consonants can be captured in this way.

Voiceless alveolar stop coarticulation in typically developing 5-year-olds and 13-year-olds

ABSTRACTIn this study, vowel-on-consonant lingual coarticulation at [t] closure offset was compared in 5-year-old children and 13-year-old adolescents. The study aimed to establish whether, by the end of the closure, children from the younger age group adjust the tongue shape to the following vowels to the same extent as adolescents. Ten 5-year-olds and ten 13-year-olds, all speakers of Scottish Standard English, produced [t]-vowel syllables with the vowels [i] and [a], in a carrier phrase. Measures of tongue shape based on midsagittal ultrasound imaging data were used to compare anticipatory coarticulation and within-speaker variability across groups. Both age groups changed the extent of tongue dorsum bunching in order to coarticulate the consonant with the following vowels. The 5-year-old children, unlike the adolescents, did not consistently modify the bunching location within the tongue curve to accommodate the tongue shape to that of the upcoming vowel. Token-to-token variability was significantly greater in the younger age group. The results suggest that vowel-on-[t] coarticulatory patterns produced by typically developing children are affected by the development of motor control, with articulatory constraints on the tongue limiting the extent of lingual coarticulation in 5-year-old children. The findings on typical coarticulation development are relevant for clinical practice, and they highlight the need for more detailed descriptions of how phonetic characteristics of speech sounds affect coarticulation throughout childhood.

Contextual place neutralization of nasal codas in Taiwanese Mandarin: An Elecrtomagentic Articulography Study

It has long been noted that /in/ and /iŋ/ are neutralized to either [in] or [iŋ] in Taiwanese Mandarin. This study aims at investigating this phenomenon and more generally, coarticulatory patterns of VN rimes ([an] and [aŋ] here) from articulatory perspectives. Kinematic data from two speakers were collected using an NDI Wave. Regarding /in/ vs. /iŋ/, a principle components analysis (PCA) was conducted to see if a specific flesh point is more positively (or negatively) related to the distinction of the tongue contours. For the female speaker, Tongue Tip (TT)-height is most positively correlated, whereas Tongue Dorsum (TD)-height is most positively correlated for the male speaker. Regarding the nasal rimes with /a/, TD-height is most positively correlated for the male speaker, while TT-backness is most negatively correlated for the female speaker. The main findings are: (i) the contextual neutralization of place contrasts in nasal codas is not articulatorily confirmed, that is, the phenomenon in question is better characterized as incomplete neutralization, (ii) there is inter-speaker variation in the implementation of articulatory gestures and (iii) “anomalous” tongue shapes are found in the production of [iŋ], suggesting that the actual coarticulatory patterns within VN rimes are more complicated than previously thought. These obtained data will also be compared with the acoustic and airflow data reported in our previous studies.

A preliminary investigation of velar-vowel coarticulation in Spanish-English Bilinguals

Coarticulation, the influence of one speech sound on another in running speech, has been suggested as an index of speech motor control. Therefore, proficient and stable coarticulation could be a diagnostic tool in language assessment and speech-language pathology. In the present study coarticulation was investigated in Spanish-English bilingual adults to determine whether velar-vowel coarticulation patterns differ in English versus Spanish. Velar-vowel coarticulation was measured in six Spanish-English bilingual university students. Participants recited sentences in blocks of English, Spanish, and a mix of both languages. Each sentence included a target word starting with /k/ + vowel. Tongue movement was recorded using a sub-mental ultrasound probe held in a stabilizing helmet. Ultrasound images were analyzed to identify tongue posture following procedures of Frisch & Wodzinski (2016, Journal of Phonetics, doi: 10.1016/j.wocn.2016.01.001). The results indicate a pattern similar to that found for Interspeech Posture in French-English bilinguals (Wilson & Gick, 2014, Journal of Speech, Language, Hearing Research, doi: 10.1044/2013JSLHR-S-12-0345). Some bilinguals showed a single pattern for both languages while others produced distinct velar postures between English and Spanish.

Investigating phonetic bases of sound patterns in Mangetti Dune !Xung: Contributions of high frame rate ultrasound to the description of endangered languages

High frame rate lingual ultrasound methods (Miller and Finch 2011) allow investigations of consonant and vowel kinematics outside of the laboratory. I summarize the results of a number of studies that investigate place and manner of articulation in consonants produced with the pulmonic and lingual airstream mechanisms in the endangered Namibian language Mangetti Dune !Xung. Results show that clicks, like dorsal stops, exhibit different postures of the posterior part of the tongue when they precede [i] and [ɑ]. The tongue dorsum and root are retracted in the production of all four coronal clicks when they precede [ɑ], but differ in their postures when they precede [i]. Further, tongue dorsum and root postures are less variable within click types before [ɑ], than they are preceding [i]. Clicks also differ in the timing of the anterior and posterior releases, resulting in different constrictions being adjacent to following vowels, thus leading to different co-articulation patterns. Timing patterns of the two...

Velar–vowel coarticulation in a virtual target model of stop production

Velar–vowel coarticulation in English, resulting in so-called velar fronting in front vowel contexts, was studied using ultrasound imaging of the tongue during /k/ onsets of monosyllabic words with no coda or a labial coda. Ten native English speakers were recorded and analyzed. A variety of coarticulation patterns that often appear to contain small differences in typical closure location for similar vowels was found. An account of the coarticulation pattern is provided using a virtual target model of stop consonant production where there are two /k/ allophones in English, one for front vowels and one for non-front vowels. Small differences in closure location along the palate between productions within each context are the result of the trajectory of movement of the tongue from the vowel to vowel through the virtual target beyond the limit of the palate. The overall pattern is thus seen as a combination of a large planned allophonic difference between consonant closure targets and smaller phonetic differences for each particular vowel quality that are the result of coarticulation.

Anticipatory coarticulation and stability of speech in typically fluent speakers and people who stutter

ABSTRACTThis project replicates and extends previous work on coarticulation in velar-vowel sequences in English. Coarticulatory data for 46 young adult speakers, 23 who stutter and 23 who do not stutter show coarticulatory patterns in young adults who stutter that are no different from typical young adults. Additionally, the stability of velar-vowel production is analysed in token-to-token variability found in multiple repetitions of the same velar-vowel sequence. Across participants, identical patterns of coarticulation were found between people who do and do not stutter, but decreased stability was found in velar closure production in a significant subset of people who stutter. Other people who stutter appeared no different than typical speakers. Outcomes of this study suggest that articulatory maturation in young adults who stutter is, on average, no different from typical young adults, but that some young adults who stutter could be viewed as having less stably activated articulatory sub-systems.

Do Isolated Vowels Represent Vowel Targets in French? An Acoustic Study On Coarticulation

Coarticulatory effects of labial, dental, palato-velar and uvular places of articulation on vowel targets of ten French oral vowels /i, e, ɛ, a, u, o, ɔ, y, o, œ/ were examined. The average vowel formant frequencies F1, F2, F3 and F4 in symmetrical sequences CVCVCVC to formant values of the same vowels in isolation were compared. The results show that the direction and magnitude of coarticulation of most vowels follow, as expected, contextual assimilation or acoustic centralization. Nevertheless, vowels /a/ and /ɔ/ present unpredictable coarticulatory patterns. This can be explained by the fact that 1) /a/ has two phonetic variants depending on the environment: back vowel [ɑ] in isolation and central/front vowel [a] in continuous speech, and 2) uttering [ɔ] in isolation violates the phonotactic rules of standard French.These results suggest that coarticulatory effects on vowels /a/ and /ɔ/ are probably not to be studied from their isolated positions.

Phonetic and phonological patterns of nasality in Lakota vowels

Lakota (Siouan) has both contrastive and coarticulatory vowel nasality, and both nasal and oral vowels can occur before or after a nasal consonant. This study examines the timing and degree patterns of acoustic vowel nasality across contrastive and coarticulatory contexts in Lakota, based on data from six Lakota native speakers. There is clear evidence of both anticipatory and carryover nasal coarticulation across oral and nasal vowels, with a greater degree of carryover than anticipatory nasalization. Nasality in carryover contexts is nonetheless restricted: the oral–nasal contrast is neutralized for high back vowels in this context and realized for three of the six speakers in low vowels. In the absence of nasal consonant context, contrastive vowel nasalization is generally greatest late in the vowel. Low nasal vowels in carryover contexts parallel this pattern (despite the location of the nasal consonantbeforethe vowel), and low nasal vowels in anticipatory contexts are most nasal at the start of the vowel. We relate the synchronic patterns of coarticulation in Lakota to both its system of contrast and diachronic processes in the evolution of nasality in Lakota. These data reflect that coarticulatory patterns, as well as contrastive patterns, are grammatical and controlled by speakers.

Strength of syllabic influences on articulation in Mandarin Chinese and French: Insights from a motor control approach

This paper investigates how strong the influences of syllables are on the organization of speech movements in Mandarin Chinese and French. More specifically, we evaluate the strength of these influences by measuring the extent of anticipatory coarticulation in V1CV2 sequences, within and across the boundaries of the CV2 syllable. In line with motor control studies that have investigated serial-order motor tasks such as speech production, we consider that the extent of anticipatory motor planning reveals information about the units of planning, their boundaries and their strengths. For V1/t/V2 and V1/k/V2 sequences, where V1 and V2 are either /i/, /a/ or /u/, we used an electromagnetic magnetometer to record articulatory data from three native speakers of Mandarin Chinese and three native speakers of French. We labeled key articulatory configurations for V1, C and V2 based on general articulatory criteria. Our two major findings are:(1)Within CV2 boundaries, coarticulation is strong for both groups of speakers; in French, the coarticulation patterns can be fully explained by anticipatory behavior, while in Mandarin Chinese other strategies might also be involved.(2)Across CV2 boundaries, anticipatory coarticulation is observed in numerous cases in French, while no significant anticipation can be noted in Mandarin Chinese. We conclude that these measures provide evidence for the hypothesis that the strength of the syllable as a unit of speech planning is more important in Mandarin Chinese than in French. Finally, we propose potential explanations for these differences.

Impact of the LSVT on vowel articulation and coarticulation in Parkinson’s disease

The purpose of this study was to investigate the impact of the Lee Silverman Voice Treatment (LSVT®) on vowel articulation and consonant–vowel (C–V) coarticulation in dysarthric speakers with Parkinson’s disease (PD). Nine Quebec French speakers diagnosed with idiopathic PD underwent the LSVT®. Speech characteristics were compared before and after treatment. Vowel articulation was measured using acoustic vowel space and calculated with the first (F1) and second formant (F2) of the vowels /i/, /u/ and /a/. C–V coarticulation was measured using locus equations, an acoustic metric based on the F2 transitions within vowels in relation to the preceding consonant. The relationship between these variables, speech loudness and vowel duration was also analysed. Results showed that vowel contrast increased in F1/F2 acoustic space after administration of the LSVT®. This improvement was associated with the gain in speech loudness and longer vowel duration. C–V coarticulation patterns between consonant contexts showed greater distinctiveness after the treatment. This improvement was associated with the gain in speech loudness only. These results support the conclusions of previous studies investigating the relationship between the LSVT®, speech loudness and articulation in PD. These results expand clinical understanding of the treatment and indicate that loud speech changes C–V coarticulation patterns. Clinical applications and theoretical considerations are discussed.

Incomplete neutralization of sibilant consonants in Penang Mandarin: A palatographic case study

It has been anecdotally observed that the three-way contrasts in Standard Chinese are reduced to two-way contrasts in Penang Mandarin (PM). PM is a variety of Mandarin Chinese spoken in Penang of Malaysia, which is influenced by Penang Hokkien. This work shows that the alleged neutralization of contrasts is incomplete (10 consonants x 3 vowel contexts x 5 speakers). More specifically, alveopalatal [ɕ] may range from postalveolar zone (73.33%) to alveolar zone (26.67%), and so does retroflex [ʂ] (46.67% vs. 46.67%). [s] and [n] are apical (or [ + anterior]) coronals. The goal of this study is three-fold: (i) to describe the places of articulation of PM coronals and the patterns of ongoing sound changes, (ii) to show the neutralization of place contrasts is incomplete whereby constriction length remains distinct for these sibilant sounds, and (iii) to demonstrate different coarticulatory patterns of consonants in variant vowel contexts. The intricate division of coronal consonants does not warrant a precise constriction location on the upper palate. This PM data lend support to Ladefoged and Wu’s (1984) observation that it is not easy to pin down a clear-cut boundary between dental and alveolar stops, and between alveolar and palatoalveolar fricatives.

Spatial and Temporal Lingual Coarticulation and Motor Control in Preadolescents

PURPOSE In this study, the authors compared coarticulation and lingual kinematics in preadolescents and adults in order to establish whether preadolescents had a greater degree of random variability in tongue posture and whether their patterns of lingual coarticulation differed from those of adults. METHOD High-speed ultrasound tongue contour data synchronized with the acoustic signal were recorded from 15 children (ages 10-12 years) and 15 adults. Tongue shape contours were analyzed at 9 normalized time points during the fricative phase of schwa-fricative-/a/ and schwa-fricative-/i/ sequences with the consonants /s/ and /ʃ/. RESULTS There was no significant age-related difference in random variability. Where a significant vowel effect occurred, the amount of coarticulation was similar in the 2 groups. However, the onset of the coarticulatory effect on preadolescent /ʃ/ was significantly later than on preadolescent /s/, and also later than on adult /s/ and /ʃ/. CONCLUSIONS Preadolescents have adult-like precision of tongue control and adult-like anticipatory lingual coarticulation with respect to spatial characteristics of tongue posture. However, there remains some immaturity in the motor programming of certain complex tongue movements.

Locus equations and the place of articulation for the Latvian sonorants

In the article, the sonorant consonants of Standard Latvian are investigated using locus equations. The aim of the study is to examine whether locus equations can be considered as efficient descriptors of consonantal place of articulation both within the group of sonorants and across different manner classes in Standard Latvian. Two-type sequences were analyzed: (1) the CV part of isolated nonsense CVC syllables, where C is one of the sonorants [m; n; ɲ; l; ʎ; r] and V is one of the vowels [i(ː); e(ː); ae(ː); ɑ(ː); ɔ(ː); u(ː)]; (2) the V(ː)C part of isolated nonsense V(ː)CV (VCV for [ŋ]) structure utterances, where C is one of the nasals [m; n; ɲ; ŋ] and V is one of the vowels [i; e; ae; ɑ; ɔ; u]. Each utterance was recorded in three repetitions by every of 10 native Latvian speakers (five males and five females), thus 3420 items were analyzed in total. Statistical analysis of locus equation slopes and y-intercepts both for the sonorants and for the whole consonant inventory of Standard Latvian was performed in order to test the relevance of these indices for discriminating places of articulation across different manner classes. By plotting the data for the whole consonant inventory in slope-by-intercept space it is possible to distinguish between the groups of palatals/dentals/alveolars and labials/velars, while the results of statistical analysis show significant difference among all place categories. According to the results, there are certain coarticulatory mechanisms associated with particular places of constriction for the Latvian consonants that allow linking locus equation data to different place categories, although they are also affected by manner and voicing. Nevertheless, place of articulation as a determinant of coarticulatory patterns overrules these factors when other possible influences are excluded.

Development of Coarticulatory Patterns in Spontaneous Speech

Development of Coarticulatory Patterns in Spontaneous Speechy