Coarticulatory Effects Research Articles

The role of coarticulatory tonal information in Cantonese spoken word recognition: an eye-tracking study

Abstract Previous eye-tracking studies suggest listeners closely track coarticulatory segmental information to facilitate spoken word recognition. In tonal languages such as Cantonese, the F0 value of high-level and rising tones is higher when preceding a low tone than preceding a high tone. Given the tonal coarticulation effect in Cantonese, this study used a printed-word version of the visual-world eye-tracking paradigm to investigate Macau Cantonese listeners’ real-time processing of coarticulatory information through two types of word pairings, in which target words and competitor words are either matched or mismatched in coarticulatory pattern (i.e., preceding a low or high tone). The results of the growth curve analysis on the difference between target and competitor fixations show that a fixation advantage of target words increases more quickly over time in the mismatch condition than in the match condition. The overall findings suggest that native listeners closely attend to the coarticulatory tonal information to facilitate lexical activation during moment-by-moment processing. Since the mechanisms of the coarticulatory effect may differ between segments and lexical tones, this research calls for further eye-tracking studies that manipulate coarticulation cues in segmental and suprasegmental domains.

A data-driven assessment of harmony in Quebec French [e] and [ε

This study is concerned with the aperture of the mid vowel /E/ in nonfinal syllables in Quebec French. The hypothesis tested is that in underived disyllabic words, the aperture of /E/ would be determined via harmony with the following vowel. Based on predictions from a classifier trained on acoustic properties of word-final vowels, nonfinal vowels were labeled as mid-close or mid-open. Although distant coarticulatory effects were observed, the harmony hypothesis was not supported. The results revealed a bias toward a mid-open quality and a reduced acoustic distinction, which warrant further investigation.

Bidirectional C-to-V coarticulation across syllable and word boundaries

Extensive work has explored the anticipatory or carryover coarticulatory effects of consonants on F2 of adjacent vowels using locus equation. However, studies examining bidirectional effects remain scarce. This study examines how voicing and place of articulation (PoA) of consonants affect bidirectional C-to-V coarticulation across syllable and word boundaries. Recordings of / C;1V;1.C;2V;2/, /C;1V;1#C;2V;2/ and /C;1V;1C;2#V;2t/ sequences from native speakers of Canadian English were analyzed. F0, F1, and F2 were measured at the onset and offset of the target vowels (/i ɑ/) to compare the coarticulatory effects caused by the adjacent consonants with different voicing and PoA (/p b t d g k/). Preliminary results (N = 6) indicate that coarticulatory effects vary based on voicing and PoA of consonants. Voiceless consonants exhibited a greater effect on f0 bidirectionally, but smaller effects on F1 and F2. Regarding PoA, only the effect of F2 in anticipatory contexts was dependent on different PoA. The findings also suggest that bidirectional coarticulatory effects are found across both syllable and word boundaries. Within and across these boundaries, larger anticipatory effects were found on f0, while the carryover effect on F1 was more robust. Concerning F2, differences between coarticulatory effects were only evident in voiceless and velar contexts.

Variability in cross-language and cross-dialect perception. How Irish and Chinese migrants process Australian English vowels.

We investigate how three adult groups- experienced L2 English listeners; experienced D2 (second dialect) listeners; and native L1/D1 listeners- categorise Australian English (AusE) lax front vowels /ɪ e æ/ in /hVt/, /hVl/ and /mVl/ environments in a forced-choice categorisation task of synthesised continua. In study 1, AusE listeners show predictable categorisations, with an effect of coarticulation raising the vowel in perception for nasal onset stimuli, and a following lateral lowering the vowel in perception. In study 2, Irish (D2) and Chinese listeners (L2) have different categorisations than AusE listeners, likely guided by their D1/L1. Coarticulation influences the D1/D2 groups in similar ways, but results in more difficulty and less agreement for the Chinese. We also investigate the role of extralinguistic factors. For the Chinese listeners, higher proficiency in English does not correlate with more Australian-like categorisation behaviour. However, having fewer Chinese in their social network results in more Australian-like categorisation for some stimuli. These findings lend partial support to the role of experience and exposure in L2/D2 contexts, whereby categorisation is likely still driven by native categories, with increased exposure leading to better mapping, but not to a restructuring of underlying phonetic categories.

Acoustic correlates of oral and glottal stops in Tahitian

The Eastern Polynesian language Tahitian spoken in French Polynesia, is described as having a simple phonological inventory with a single stop series: /p, t, ʔ/. Little is known about the acoustic properties of these consonants compared to well-resourced languages. Five female speakers of Tahitian produced multiple repetitions of tokens that varied in terms of stress location and prosodic phrase position. Acoustic analyses of stop duration and VOT, as well as voicing measures including voicing fraction and strength of excitation were conducted. As predicted, oral stops were significantly longer than glottal stops by 63 ms in word medial contexts with no effect of stress. VOT values were on average 21–26 ms (with /t/ marginally longer than /p/) confirming these are short lag stops (Cho and Ladefoged, 1999). Stress was marginally significant with shorter VOT values in stressed syllable onsets with no affect of prosodic position, unlike Hawaiian (Davidson and Parker Jones, 2022). Like Hawaiian, however, (Davidson, 2021), the glottal stop in Tahitian has gradient realizations although the majority are realised with full glottal closure with low voicing fraction and strength of excitation values. There are also clear effects of greater coarticulation in unstressed versus stressed syllables suggesting localised hyperarticulation in the latter context.

Emphasis spread: The domain and trigger

This paper investigates the domain and directionality of emphasis spread in Urban Jordanian Arabic. The acoustic coarticulatory effects of emphasis are also probed. Nine native speakers of the dialect were recorded reading tri-syllabic monomorphemic and bimorphemic minimal pairs. The minimal pairs contained the voiceless emphatic fricative/sˁ/and its plain counterpart/s/in word initial and word final contexts. The acoustic correlates of emphasis measured were F1, F2, and F3 in the vowels following (i.e., word-initial) and preceding the emphatic sound (i.e., word-final). The results have roughly corroborated our findings in previous research where we claimed that the morpheme is, though disproportionately, still a confounding factor of emphasis spread. The most interesting contribution of this research is the perplexing behavior of emphasis spreading when crossing over the morpheme boundaries. Whereas the influence of the emphatic sound is evident on the morpheme falling to its left (e.g. prefixes) is evident, its influence on the morpheme falling to its right (i.e. suffixes) is less clear. In other words, one could argue that the boundary between the stem and the suffix is more robust compared to the boundary between the stem and the prefix. Therefore, a line of demarcation, we hypothesize, should be drawn between suffix boundary and prefix boundary.

The vowel system of Qatari Arabic: Evidence for peripheral/non-peripheral distinction between long and short vowels

Arabic has a vowel system with three long and three short monophthongs. One of the parameters that accounts for qualitative differences between long and short vowels across languages is tenseness/laxness of vowels located on the peripheral/non-peripheral tracks in the vowel space. The present study investigates acoustical cues (F1, F2, and duration) of vowels using the data obtained from 21 speakers of Qatari Arabic. The vowels were produced in four phonetic contexts: labial, alveolar, uvular, and pharyngeal. The results revealed considerable qualitative differences between long and short vowels. The long vowels were articulated at the periphery of vowel space; the short vowels occupied more centralized positions. The co-articulatory effect of the preceding consonant was more prominent in short vowels. Short high vowels /i u/ were lowered toward the mid position; short low /a/ was fronted; long low /aː/ was retracted and raised. The findings suggest that short vowels in Qatari Arabic are lax and non-peripheral.

A preliminary study on the online processing of anticipatory tonal coarticulation - Evidence from eye movements.

While the f0 realization of lexical tones vary extensively in contexts, little has been known on how listeners process the variation in lexical tones due to contextual effects such as tonal coarticulation in spoken word recognition. This study thus aims to fill the knowledge gap in tone perception with evidence from two types of anticipatory tonal coarticulation effects in Tianjin Mandarin, i.e., the slope raising effect due to a following low-falling tone and the overall-height raising effect due to a following low-dipping tone. An eye-tracking experiment with the Visual World Paradigm was carried out to compare participants' eye movements when they heard targets in three types of anticipatory raising conditions, i.e., the Slope Raising condition, the Overall-height Raising condition, as well as the No Raising condition (the baseline). The eye movement results showed significant differences in the proportion of looks to target between the Slope Raising condition versus the other two conditions, whereas the Overall-height Raising condition did not differ significantly from the No Raising condition. The findings thus suggest the facilitatory effect of tonal coarticulation cues in the anticipation of the upcoming tones, but listeners in this study seemed to be only sensitive to the raising in the f0 slope rather than the overall raising in the f0 height.

Covariants of Gemination in Eastern Andalusian Spanish: /t/ following Underlying /s/, /k/, /p/ and /ks/

In Eastern Andalusian Spanish, consonants are deleted in syllable-final position, triggering regular gemination of a following consonant, even across word boundaries. This paper investigates five underlying phonemic contexts involving /t/, including singleton /t/ and four different underlying /C+t/ sequences that typically surface as [t:], by analyzing how durational and formant differences vary depending on the presence and identity of the preceding underlying consonant. Following the acoustic and statistical analyses of 444 instances of /ˈeta/, /ˈesta/, /ˈekta/, /ˈepta/ and /ˈeksta/, a Discriminant Function Analysis shows that differences in the total duration of /t/ and in the duration of the closure of /t/ are the strongest cues to distinguishing singletons from geminated consonants, with 91.9% and 90.6% accurate classifications, respectively. Cues indicating which specific consonants have been deleted before /t/ are much less robust and more varied in nature. It is unclear, however, whether this outcome is due to different compensation strategies in each case or whether they are affected by some kind of underlying coarticulatory effect. Given that gemination in this language variety is the result of regular /C1C2/ to [Cː] assimilation, and that its underlying phonemic status has not been demonstrated, Eastern Andalusian Spanish is unusual amongst languages studied with respect to gemination, making this study typologically interesting.

모음 스펙트럼에 기반한 전후 비자음 조음위치 판별*

This study examined the utility of the acoustic features of vowels as cues for the place of articulation of Korean nasal consonants. In the acoustic analysis, spectral and temporal parameters were measured at the 25%, 50%, and 75% time points in the vowels neighboring nasal consonants in samples extracted from a spontaneous Korean speech corpus. Using these measurements, linear discriminant analyses were performed and classification accuracies for the nasal place of articulation were estimated. The analyses were applied separately for vowels following and preceding a nasal consonant to compare the effects of progressive and regressive coarticulation in terms of place of articulation. The classification accuracies ranged between approximately 50% and 60%, implying that acoustic measurements of vowel intervals alone are not sufficient to predict or classify the place of articulation of adjacent nasal consonants. However, given that these results were obtained for measurements at the temporal midpoint of vowels, where they are expected to be the least influenced by coarticulation, the present results also suggest the potential of utilizing acoustic measurements of vowels to improve the recognition accuracy of nasal place. Moreover, the classification accuracy for nasal place was higher for vowels preceding the nasal sounds, suggesting the possibility of higher anticipatory coarticulation reflecting the nasal place.

Emphasis spread in Arabic: The domain and trigger

Acoustic coarticulatory effects of emphasis, a secondary articulation in the posterior vocal tract simultaneously accompanying a primary one, were investigated in Urban Jordanian Arabic. Nine native speakers of the dialect were recorded reading tri-syllabic monomorphemic and bimorphemic minimal pairs. The minimal pairs contained the voiceless emphatic fricative /sʕ/ and its plain counterpart /s/ in word initial and word final contexts. The acoustic correlates of emphasis include a raised F1, lowered F2, and raised F3 in the vowels preceding and following the emphatic sound. The results have roughly corroborated our findings in the previous research that the morpheme is, though disproportionately, still a confounding factor of emphasis spread. The most interesting contribution of this research is the perplexing behavior of emphasis spreading when crossing over the morpheme boundaries. Whereas the influence of the emphatic sound is evident on the morpheme falling to its left (e.g., prefixes) is evident, its influence of the morpheme falling to its right (i.e., suffixes) is less clear. This amounts to saying that the morpheme boundary between the stem and the suffix is stronger than that between the stem and the prefix. What this means is that a line of demarcation should be drawn between suffix boundary and prefix boundary.

Lithuanian and Latvian laterals: Comparison of acoustic properties

The aim of the paper is to examine how acoustic contrast manifests itself between /l/ and /ʎ/ in Latvian, as well as /l/ and /lʲ/ in Lithuanian. For the study, speech recordings of 6 adult informants (3 Lithuanian and 3 Latvian male speakers) have been analysed. Initial and final laterals in closed symmetric [l]V[l] sequences and intervocalic syllable-initial laterals in V[l]V sequences have been examined. During the analysis, the focus is placed mainly on locus equations, as well as changes in formant structure (especially F1 and F2) triggered by position and vocalic context. Acoustic data demonstrates differences in coarticulation effects between Latvian palatal /ʎ/ and Lithuanian palatalized /lʲ/. The formant structure of /ʎ/ and /lʲ/, unlike the corresponding non-palatal laterals, is more stable and less dependent on the quality of adjacent vowels. Vowel context affects the degree of palatalization, e. g. palatalized [lʲ] next to [ɪ], [iː] and [eː] is pronounced “softer” than next to [ɔ̟], [o̟ː], [ʊ̟], and [u̟ː]. Latvian /ʎ/ is characterized by a more stable vowel F2 locus, which indicates higher degree of coarticulatory resistance to vowel effects; the quality of /lʲ/, on the contrary, depends more on vowel context. The same is true (although to lesser degree) for the Lithuanian /l/. The assumption about the similarity of Latvian non-palatal /l/ and Lithuanian palatalized /lʲ/ is only partly supported by the recent data. In terms of the degree of coarticulation (indicated by slope values of locus equations), Latvian /l/ is closer to Lithuanian /lʲ/, while its formant structure, especially low F2, brings it closer to Lithuanian /l/.

Prosodic modulations on the formant excursions of diphthongs

The excursions of the first two formants of diphthongs in Chinese, English, and Japanese were investigated to see how diphthongs are affected by the hierarchical prosodic structure. The production of /ai, au, ou/ was examined in Chinese and English, and /ai, au, ae/ in Japanese. Three prosodic contexts were examined: word-final, list-final, and IP (intonational phrase)-final positions. The results of GAM analysis of F1 and F2 show that (1) F2 was more affected than F1; (2) diphthong offset was more affected than the onset; (3) only the diphthong onset in Japanese was affected by the prosody. The by-language analysis further shows that the offset of diphthongs at word-final positions in Chinese was less resistant to the coarticulatory effect: F2 raises earlier and higher toward the end of the diphthong due to the influence of the following coronal consonant. Meanwhile, in English and Japanese /ai, ae/ with lower F2 and higher F1 and /au, ou/ with higher F1 and F2 at word-final positions were found, indicating hypoarticulation at lower prosodic boundaries. Some of the diphthong onsets in Japanese were influenced as well. The result suggests hyperarticulation as a prosodic strengthening effect in English and Japanese.

Production of gutturals by non-native speakers of Arabic

This paper investigates the production of Arabic gutturals by native (NSs) and non-native speakers (NNSs) of Arabic. A total of 40 participants, 20 NSs and 20 NNSs were recruited. 240 tokens were collected using two major methods: free speech and nonsense word testing. Using PRAAT software (version 6.1.01), the tokens were analyzed acoustically to measure F1 and F2 and to signal the (non)significance of the difference between the target groups and auditorily to rate gutturals’ production accuracy by NNSs. F1 and F2 of the vowels neighbouring the gutturals were normalized using the speaker extrinsic Labov ANAE method (NORM version 1.1) to eliminate the effects of gender and age. The study demonstrates some important findings: in terms of quality, the F1-F2 approximation varies by nativeness in that NNSs were unable to make enough coarticulatory effects associated with Arabic gutturals. This result indicates that NNSs do not make a sufficient primary constriction in the posterior regions of the vocal tract. Relying on auditory judgments of accuracy, the most accurately produced gutturals by NNSs were the voiceless glottal fricative /h/ followed by the voiceless glottal plosive /ʔ/, and the lowest ranked gutturals were the voiced velar fricative /ɣ/ and the voiced pharyngeal fricative /ʕ/. The study concludes that non-temporal cues especially F1 and F2 are essential correlates to Arabic gutturals’ production. Because such factors are language-specific, they should be taken into consideration in the teaching of Arabic as a second/foreign language.

Acoustic correlates and listener ratings of function word reduction in child versus adult speech.

The present study investigated "the" reduction in phrase-medial Verb-the-Noun sequences elicited from 5-year-old children and young adults (18-22 yr). Several measures of reduction were calculated based on acoustic measurement of these sequences. Analyses on the measures indicated that the determiner vowel was reduced in both child and adult speech relative to content word vowels, but it was reduced less in child speech compared to adult speech. Listener ratings on the sequences indicated a preference for adult speech over children's speech. Acoustic measures of reduction also predicted goodness ratings. Listeners preferred sequences with shorter and lower amplitude determiner vowels relative to content word vowels. They also preferred a more neutral schwa over more coarticulated versions. In sequences where ratings differed by age group, the effect of coarticulation was limited to adult speech and the effect of relative schwa duration was limited to child speech. The results are discussed with reference to communicative pressures on speech, including the rhythmic and semantic pressures towards reduction versus the pressure to convey adequate information in the acoustic signal. It is argued that these competing pressures on production may delay the acquisition of adult-like function word reduction.

Developmental Changes in Coarticulation Degree Relate to Differences in Articulatory Patterns: An Empirically Grounded Modeling Approach.

Coarticulatory effects in speech vary across development, but the sources of this variation remain unclear. This study investigated whether developmental differences in intrasyllabic coarticulation degree could be explained by differences in children's articulatory patterns compared to adults. To address this question, we first compared the tongue configurations of 3- to 7-year-old German children to those of adults. The observed developmental differences were then examined through simulations with Task Dynamics Application, a Task Dynamics simulation system, to establish which articulatory modifications could best reproduce the empirical results. To generate syllables simulating the lack of tongue gesture differentiation, we tested three simulation scenarios. We found that younger speakers use less differentiated articulatory patterns to achieve alveolar constrictions than adults. The simulations corresponding to undifferentiated control of tongue tip and tongue body resulted in (a) tongue shapes similar to those observed in natural speech and (b) higher degrees of intrasyllabic coarticulation in children when compared to adults. Results provide evidence that differences in articulatory patterns contribute to developmental differences in coarticulation degree. This study further shows that empirically informed modeling can advance our understanding of changes in coarticulatory patterns across age.

Sonorant spectra and coarticulation distinguish speakers with different dialects

This study aims to determine the effect of language varieties on the spectral distribution of stressed and unstressed sonorants (nasals /m, n/, lateral approximants /l/, and rhotics /r/) and their coarticulatory effects on adjacent sounds. To quantify the shape of the spectral distribution, we calculated the spectral moments from the sonorant spectra of nasals /m, n/, lateral approximants /l/, and rhotics /r/ produced by Athenian Greek and Cypriot Greek speakers. To estimate the co-articulatory effects of sonorants on the adjacent vowels' F1 - F4 formant frequencies, we developed polynomial models of the adjacent vowel's formant contours. All sonorants had distinct effects on adjacent vowel formant contours, especially for F3 and F4. The study highlights that the combination of spectral moments and coarticulatory effects of sonorants determines sonorants' linguistic (stress and phonemic category) and sociolinguistic (language variety) characteristics. It also provides the first comparative acoustic analysis of Athenian Greek and Cypriot Greek sonorants.

Acoustic Cues of /ħ/ and /ʕ/ in Hourani Jordanian Arabic: Investigating Sociolinguistic Variation

This paper examines the interaction between the coarticulatory effects of pharyngeals on adjacent vowels and the speakers’ age and gender in Hourani Jordanian Arabic. To this end, 28 participants were recorded reading a list of 24 words containing a pharyngeal sound (/ħ/ or /ʕ/) preceded (word-finally) or followed (word-initially) by a short or long vowel. A total of 1344 tokens were extracted and then analyzed in PRAAT. The first three formant frequencies (F1, F2, F3) of each vowel were manually measured at the midpoint. The measurements were then normalized using Nearey’s (1977) intrinsic formula to reduce the effect of physiological differences between male and female speakers. The findings of the study show no significant effects of age or gender on the production of the adjacent vowels word-initially or word-finally. This suggests that, unlike the case of pharyngealized sounds (e.g., Omari and Jaber (2019)), pharyngeal-to-vowel coarticulation is not affected by the sociolinguistic variables of age and gender. Keywords: Coarticulation; Extralinguistic variables; Hourani Jordanian Arabic; Pharyngeals.

Maintenance of phonetic and phonological distance in the English and Korean back vowel contours of heritage bilinguals

Bilingualism research demonstrates that the potential merger of vowel categories across a speaker’s two languages is affected by the age of acquisition of the second language. For heritage bilinguals, however, there is no clear L1 and L2, since they acquire their heritage language in early childhood, but become dominant in the mainstream language of society as adults. Heritage bilinguals may nevertheless will acquire distinct vowel systems in their two languages, rather than a merged system. In this study, the back vowels of California English and Seoul Korean, two varieties that are spoken by bilingual second-generation Korean Americans in California, were collected in natural speech. Formant measurements were analyzed using linear mixed effects regression modeling and generalized additive mixed modeling to see whether the vowels of each language were similar or different in their formant contours. As predicted, the bilinguals maintained distance between the vowels of both languages across their durations, and the phonological effects of coarticulation were found to be stronger in English than in Korean. The differences are attributed to “multicompetence” in heritage bilinguals’ phonology (Cook, 2020), or the interrelationship of multiple systems that exist and interact in the bilingual mind without merging completely, in opposition to models that frame heritage bilingualism as inherently imbalanced in favor of the dominant language.

Dissimilatory interactions among lexical tones are mediated by speech rate: Evidence from Thai

The pitch targets of lexical tones in adjacent syllables exhibit interactions that are reminiscent of the coarticulatory effects typical of segments (Gandour, 1994; Xu, 1994). However, unlike segmental coarticulation, which is primarily assimilatory, lexical tones also exhibit dissimilatory interactions. For instance, tones with a high pitch target have been reported to reach even higher targets before a dissimilar low tone than before a similar high tone; a phenomenon known as pre-low raising (Lee et al., 2021). Our contribution focuses on two aspects of tonal coarticulation: the existence of dissimilatory pre-high lowering effects, and the role of speech ratein coarticulatory effects. A production experiment was conducted with 20 speakers of Bangkok Thai, who produced disyllabic combinations of Falling/Rising tones before all the five tones of the language (Mid/Low/Falling/High/Rising) in carrier sentences at a variety of speech rates. Results show the existence of both pre-low raising and pre-high lowering dissimilatory effects in Bangkok Thai. Further, the dissimilatory effects are weaker at higher speech rates. The interaction between speech rate and the strength of dissimilatory effects suggests that tonal dissimilation may be primarily driven by articulatory target planning mechanisms rather than perceptual enhancement (Lee et al., 2021).