Consonantal Context Research Articles

Effects of Individual difference and L1 phonology on the identification and discrimination of American English vowels by native Japanese and Korean listeners

Native speakers of Japanese and Korean identified and discriminated American English vowels /i, ɪ, ɛ, ae, ɑ, ʌ/ in four different consonantal contexts. These listeners also perceptually assimilated the American English vowels to their respective L1 vowel categories. In another session, these listeners produced /i, ɪ, ɛ, ae, ɑ, ʌ/ in two different conditions. They read aloud words on a list, and they repeated after native speakers' utterances. The results revealed that Korean listeners as well as Japanese listeners rely on durational difference to identify and discriminate /i/ and /ɪ/, but Korean listeners perceptually assimilated /i/ and /ɪ/ as roughly equally good exemplars of Korean high front vowel. Japanese listeners, on the other hand, perceived /ɪ/ as somewhat less ideal exemplar of Japanese high front vowel than /i/. However, those Japanese listeners who were sensitive to spectral differences did not outperform those who were less sensitive. Moreover, Japanese listeners sensitive to the spectral differences often misidentified /ɪ/ for /ɛ/. An MDS analysis revealed that in the identification task, listeners’ L1 phonology exercise a stronger influence than do individual differences, but in discrimination task, individual differences are as strong a factor as listeners’ L1 phonology.

Vowel Formants in Normal and Loud Speech.

Purpose This study evaluated how 1st and 2nd vowel formant frequencies (F1, F2) differ between normal and loud speech in multiple speaking tasks to assess claims that loudness leads to exaggerated vowel articulation. Method Eleven healthy German-speaking women produced normal and loud speech in 3 tasks that varied in the degree of spontaneity: reading sentences that contained isolated /i: a: u:/, responding to questions that included target words with controlled consonantal contexts but varying vowel qualities, and a recipe recall task. Loudness variation was elicited naturalistically by changing interlocutor distance. First and 2nd formant frequencies and average sound pressure level were obtained from the stressed vowels in the target words, and vowel space area was calculated from /i: a: u:/. Results Comparisons across many vowels indicated that high, tense vowels showed limited formant variation as a function of loudness. Analysis of /i: a: u:/ across speech tasks revealed vowel space reduction in the recipe retell task compared to the other 2. Loudness changes for F1 were consistent in direction but variable in extent, with few significant results for high tense vowels. Results for F2 were quite varied and frequently not significant. Speakers differed in how loudness and task affected formant values. Finally, correlations between sound pressure level and F1 were generally positive but varied in magnitude across vowels, with the high tense vowels showing very flat slopes. Discussion These data indicate that naturalistically elicited loud speech in typical speakers does not always lead to changes in vowel formant frequencies and call into question the notion that increasing loudness is necessarily an automatic method of expanding the vowel space. Supplemental Material https://doi.org/10.23641/asha.8061740.

Características acústicas de las vocales tónicas y átonas del español rioplatense. Efectos del estilo de habla y del contexto consonántico

Produced vowels in a style focused on speech (isolated words reading) exhibit more peripheral formants and more spectral change than conversational vowels (text reading). This study explored the interaction between lexical stress and speech style by comparing the production of stressed and unstressed /a e o/ River Plate Spanish vowels produced by word reading versus the text reading in three different consonantal contexts. Formant frequency in the stable point of the vowel (50%) and spectral change were examined. Results revealed that speech style mainly affected the F2 of stressed and unstressed vowels /e/ and /o/. In the word reading, /e/ was more anterior and /o/ more posterior. Nevertheless, this modification in the F2 due to speech style was not observed in all the consonantal contexts. Regarding F1, only stressed /a/ increased its F1 in word reading in relation to conversational speech, independent of the phonetic context. Concerning the effect of the lexical stress, stressed /a/ and /o/ were produced with a higher F1 than the unstressed counterparts, while stressed /e/ showed a higher F2 than unstressed /e/. As for the spectral change, vowels /a/ and /o/ evinced a higher spectral variation in the word reading than in text reading, unlike /e/ that showed an opposite pattern. Only the unstressed /a/ in bilabial context had a greater spectral change than the stressed /a/.

On the development of gestural organization: A cross-sectional study of vowel-to-vowel anticipatory coarticulation.

In the first years of life, children differ greatly from adults in the temporal organization of their speech gestures in fluent language production. However, dissent remains as to the maturational direction of such organization. The present study sheds new light on this process by tracking the development of anticipatory vowel-to-vowel coarticulation in a cross-sectional investigation of 62 German children (from 3.5 to 7 years of age) and 13 adults. It focuses on gestures of the tongue, a complex organ whose spatiotemporal control is indispensable for speech production. The goal of the study was threefold: 1) investigate whether children as well as adults initiate the articulation for a target vowel in advance of its acoustic onset, 2) test if the identity of the intervocalic consonant matters and finally, 3) describe age-related developments of these lingual coarticulatory patterns. To achieve this goal, ultrasound tongue imaging was used to record lingual movements and quantify changes in coarticulation degree as a function of consonantal context and age. Results from linear mixed effects models indicate that like adults, children initiate vowels’ lingual gestures well ahead of their acoustic onset. Second, while the identity of the intervocalic consonant affects the degree of vocalic anticipation in adults, it does not in children at any age. Finally, the degree of vowel-to-vowel coarticulation is significantly higher in all cohorts of children than in adults. However, among children, a developmental decrease of vocalic coarticulation is only found for sequences including the alveolar stop /d/ which requires finer spatiotemporal coordination of the tongue’s subparts compared to labial and velar stops. Altogether, results suggest greater gestural overlap in child than in adult speech and support the view of a non-uniform and protracted maturation of lingual coarticulation calling for thorough considerations of the articulatory intricacies from which subtle developmental differences may originate.

Effects of consonantal context on the learnability of vowel categories from infant-directed speech.

Recent studies have shown that vowels in infant-directed speech (IDS) are characterized by highly variable formant distributions. The current study investigates whether vowel variability is partially due to consonantal context, and explores whether consonantal context could support the learning of vowel categories from IDS. A computational model is presented which selects contexts based on frequency in the input and generalizes across contextual categories. Improved categorization performance was found on a vowel contrast in American-English IDS. The findings support a view in which the infant's learning mechanism is anchored in context, in order to cope with acoustic variability in the input.

How Do Children Organize Their Speech in the First Years of Life? Insight From Ultrasound Imaging.

This study reports on a cross-sectional investigation of lingual coarticulation in 57 typically developing German children (4 cohorts from 3.5 to 7 years of age) as compared with 12 adults. It examines whether the organization of lingual gestures for intrasyllabic coarticulation differs as a function of age and consonantal context. Using the technique of ultrasound imaging, we recorded movement of the tongue articulator during the production of pseudowords, including various vocalic and consonantal contexts. Results from linear mixed-effects models show greater lingual coarticulation in all groups of children as compared with adults with a significant decrease from the kindergarten years (at ages 3, 4, and 5 years) to the end of the 1st year into primary school (at age 7 years). Additional differences in coarticulation degree were found across and within age groups as a function of the onset consonant identity (/b/, /d/, and /g/). Results support the view that, although coarticulation degree decreases with age, children do not organize consecutive articulatory gestures with a uniform organizational scheme (e.g., segmental or syllabic). Instead, results suggest that coarticulatory organization is sensitive to the underlying articulatory properties of the segments combined.

Early neural responses underlie advantages for consonance over dissonance

Consonant musical intervals tend to be more readily processed than dissonant intervals. In the present study, we explore the neural basis for this difference by registering how the brain responds after changes in consonance and dissonance, and how formal musical training modulates these responses. Event-related brain potentials (ERPs) were registered while participants were presented with sequences of consonant intervals interrupted by a dissonant interval, or sequences of dissonant intervals interrupted by a consonant interval. Participants were musicians and non-musicians. Our results show that brain responses triggered by changes in a consonant context differ from those triggered in a dissonant context. Changes in a sequence of consonant intervals are rapidly processed independently of musical expertise, as revealed by a change-related mismatch negativity (MMN, a component of the ERPs triggered by an odd stimulus in a sequence of stimuli) elicited in both musicians and non-musicians. In contrast, changes in a sequence of dissonant intervals elicited a late MMN only in participants with prolonged musical training. These different neural responses might form the basis for the processing advantages observed for consonance over dissonance and provide information about how formal musical training modulates them.

Development and Prediction of Context-Dependent Vowel Pronunciation in Elementary Readers

ABSTRACTAs children learn to read, they become sensitive to context-dependent vowel pronunciations in words, considered a form of statistical learning. The work of Treiman and colleagues demonstrated that readers’ vowel pronunciations depend on the consonantal context in which the vowel occurs and reading experience. Using explanatory item-response models we examined child- and nonword-factors associated with children’s assignment of more versus less frequent grapheme-phoneme correspondences (GPC) to vowel pronunciations as a function of rime coda in monosyllabic nonwords. Students (N = 96) in grades 2-5 read nonwords in which more versus less frequent vowel GPCs were wholly supported or partially favored by the rime unit. Use of less frequent vowel GPCs was predicted by set for variability, word reading, and rime support for the context-dependent vowel pronunciation. We interpret the results within a developmental word reading model in which initially incomplete and oversimplified GPC representations become more context dependent with reading experience.

Shifting from the shift: Loss of dialect distinction in the US

Historically, /ae/ in the Northern Cities Shift (NCS) dialect area is realized as raised, lengthened, and diphthongized in all consonantal contexts (Boberg and Strassel 2000) and that pre-oral /ae/ is realized with as much nasalization as pre-nasal /ae/ (Plichta 2004). Recent studies suggest that young speakers in the dialect area are adopting a nasal pattern for /ae/ such that only tokens before nasal consonants are raised and fronted in phonetic space (in Lansing, MI (Wagner et al. 2016), in Syracuse, NY (Driscoll and Lape 2015), in Upstate NY (Thiel and Dinkin 2017), in Detroit, MI (Acton et al. 2017)). Through acoustic analysis of 1310 /ae/ tokens produced by 26 speakers born and raised in Lansing, MI (date of birth 1991–1997), the current study finds that younger speakers are not simply lowering and retracting this vowel, they are rejecting all phonetic components of the NCS /ae/ system. For these speakers, only pre-nasal /ae/ tokens are realized as long, diphthongal, and nasalized, while pre-oral tokens are short, monophthongal, and have little to no nasalization. Vowel quality for /ae/ in the NCS dialect area is thus undistinguishable from that in the western and midland states in the US (e.g., California and Kansas).

Vowel-to-vowel coarticulation in Spanish non-words: Effects of stress and consonantal context

In spoken language, gestural overlap in speech production regularly leads to coarticulation between neighboring segments, resulting in assimilation measurable by changes in the acoustic parameters. Vowels in adjacent syllables can coarticulate in a phenomenon called vowel-to-vowel coarticulation, which is subject to variation based on environmental factors such as surrounding consonantal context and the placement of stress. This study investigates vowel-to-vowel coarticulation in Spanish in order to better understand the effect of stress and consonantal context on coarticulation. Formant analysis of vowels produced by 20 native speakers of Spanish was used to determine the presence and direction of coarticulation in trisyllabic nonce words with varying stress (/CVCVCV/ words, vowels /e, o/ as targets and /e, i, o, u/ as triggers, /k/ and /p/ contexts). Results showed that both anticipatory and carryover vowel-to-vowel coarticulation was present at vowel edges in all contexts, but only carryover coarticulation in backness extended to vowel midpoints. Stress placement mediated the coarticulatory effect with select target and trigger combinations in carryover coarticulation, while consonantal context played a greater role in anticipatory coarticulation. When stress played a role, unstressed target vowels were more susceptible to coarticulation, while stressed targets resisted coarticulatory effects.

The emergence of a new pronunciation variant in a culturally changing appalachian community

The dialect spoken in the small southern Appalachian community in Western North Carolina, formally a part of the Inland South, represents the most archaic features of Southern English, including monophthongization of the diphthong /ai/ to [a:]. While Southerners produce the monophthong before voiced consonants (“prize”) all across the South, pre-voiceless monophthongization (“price”) is more restricted and still occurs in the Inland South. However, as the local culture is gradually shifting toward new mainstream sociocultural norms, so does the local dialect. To document the sound change in progress, this acoustic study examined the /ai/-monophthongization across several generations of local speakers ranging from 8 to 91 year olds, 58 males and 60 females, using a style shifting paradigm. Older generations produced the monophthong irrespective of speaking style and consonant context. Young adults introduced the diphthongal variant in pre-voiceless context. The actual departure from the monophthong occurre...

The <i>loi de position</i> and the acoustics of French mid vowels

This paper reports the results of two experiments on the acoustics of French mid vowels in a variety in which close-mid vowels ([e], [ø], [o]) occur in open syllables and open-mid vowels ([ɛ], [oe], [ɔ]) in closed syllables, according to the loi de position. Open-mid allophones have consistently higher F1 realizations and more central F2 realizations than their close-mid counterparts, but are not consistently shorter. These results are problematic for accounts of the loi de position as a pattern of vowel reduction, with mid-vowel lowering and centralizing being caused by shortening. F1 and F2 distances between close-mid and open-mid allophones vary across different prosodic and consonantal contexts and these variations can be analyzed as resulting from duration-based undershoot. More broadly, the results have implications for the typology of closed-syllable vowel laxing: they suggest that tense and lax realizations cannot generally be derived from the same acoustic target via closed-syllable vowel shortening but have distinct acoustic targets.

Fronting of Southern British English high-back vowels in articulation and acoustics.

The fronting of the two high-back vowels /uː/ and /ʊ/ in Southern British English is very well documented, but mainly in the acoustic domain. This paper presents articulatory (ultrasound) data, comparing the relative tongue position of these vowels in fronting and non-fronting consonantal contexts, i.e., preceding a coronal consonant (food, foot) and preceding a coda /l/ (fool, full). Particular attention is paid to the comparison between articulatory results and corresponding acoustic measurements of F2 in both vowels. Results show that the average differences between food and foot and their dynamic profiles are similar in articulation and acoustics. In /uːl/ sequences (fool), tongue position is more advanced than could be inferred from its low F2. In addition, even though the tongue position in fool and full is clearly distinct, there is no comparable corresponding difference in F2. This suggests that the common articulatory metaphor that characterises F2 increase as fronting must be used cautiously. In the case of English high-back vowel fronting, special attention must be paid to the flanking consonants when estimating vowel distances. This paper also provides specific recommendations for recording and analysing ultrasound data in research on vowel variation and change.

Modeling consonant-context effects in a large database of spontaneous speech recordings.

Given recent interest in the analysis of naturally produced spontaneous speech, a large database of speech samples from the Canadian Maritimes was collected, processed, and analyzed with the primary aim of examining vowel-inherent spectral change in formant trajectories. Although it takes few resources to collect a large sample of audio recordings, the analysis of spontaneous speech introduces a number of difficulties compared to that of laboratory citation speech: Surrounding consonants may have a large influence on vowel formant frequencies and the distribution of consonant contexts is highly unbalanced. To overcome these problems, a statistical procedure inspired by that of Broad and Clermont [(2014). J. Phon. 47, 47-80] was developed to estimate the magnitude of both onset and coda effects on vowel formant frequencies. Estimates of vowel target formant frequencies and the parameters associated with consonant-context effects were allowed to vary freely across the duration of the vocalic portion of a syllable which facilitated the examination of vowel-inherent spectral change. Thirty-five hours of recorded speech samples from 223 speakers were automatically segmented and formant-frequency values were measured for all stressed vowels in the database. Consonant effects were accounted for to produce context-normalized vowel formant frequencies that varied across time.

Allophonic variation of Polish vowels in the context of prepalatal consonants

Phonetic studies of Polish mention allophonic variation in Polish vowels, in that there is a systematic effect of the prepalatal consonant context. In particular, [u] is fronted, [ɛ] is raised, [a] is fronted and sometimes raised, and [ɔ] is fronted following a prepalatal consonant. Additionally, phonemic [i] is excluded after non-palatalized consonants, and the phonemic [ɨ] does not occur after prepalatals. Although X-ray data for Polish speech production exists from the 50s and 60s, no X-ray images are available of the contextual variants of vowels adjacent to prepalatal consonants. In this study, we present 3-D tongue shapes of the vowels in neutral and prepalatal contexts. The data show a combination of raising and fronting of the tongue body for all front vowels, and also a consistent effect of tongue root advancement.

Étude acoustique et perceptive des voyelles du français réalisées par des apprenants jordaniens et des locuteurs français

The research contains a comparative study of French oral vowels realized by French native speakers and Jordanian Arabic-speaking learners, as well as tests of identification for the nasal vowels produced by the learners and recognized by native listeners of French. The acoustic study of French oral vowels in isolated and consonantal context demonstrates that Jordanian learners experience difficulties in reproducing suitably the vowels /o - oe/ which do not exist in the phonological system of Arabic and the vowel /u/ which is deformed in the production of the learners despite the fact that it has a phonological counterpart in Arabic. The results also reveal that the learners master only a single sound of the intermediate vowels /e - ɛ / and /o - ɔ/. Perceptual tests of identification indicate that Jordanian learners confuse, in pronunciation, between both nasal vowels /ɑ ɔ/. So, it is necessary that acoustic and articulatory phonetics techniques be integrated alongside with strategies to correct the deviant realizations in the learners’ production. Key words: Acoustic study, French vowels, pronunciation teaching, Jordanian students.

Target-locus scaling for modeling formant transitions in vowel + consonant + vowel utterances.

The coarticulatory effects described by Öhman [J. Acoust. Soc. Am. 39, 151-168 (1966)] imply that consonant loci cannot always be defined by their associated consonantal contexts alone, but, in Swedish vowel + consonant + vowel utterances, they must also depend on their trans-consonantal vowels (TCVs). His discovery is extended here using a model with TCV-dependent consonant loci and with a unique target for each vowel. The model accurately characterizes the vowel-to-consonant and consonant-to-vowel transitions for the /b/ and /d/ contexts from Öhman's second formant-frequency data as families connected by linear-scaling relationships.

Individual differences in the production of nasal coarticulation and perceptual compensation

The current study investigates correlations between individual differences in the production of nasal coarticulation and patterns of perceptual compensation in American English. A production study (Experiment 1) assessed participants’ nasal coarticulation repertoires by eliciting productions of CVC, CVN and NVN words. Stimuli for two perception tasks were created by cross-splicing oral vowels (from C_C words), nasal vowels (from C_N words), and hypernasal vowels (from N_N words) into C_C, C_N, and N_N consonant contexts. Stimuli pairs were presented to listeners in a paired discrimination task (Experiment 2), where similarity of vowels was assessed, and a nasality ratings task (Experiment 3), where relative nasalization of vowels was judged. In the discrimination task, individual differences in produced nasal coarticulation predicted patterns of veridical acoustic perception. Individuals who produce less extensive anticipatory nasal coarticulation exhibit more veridical acoustic perception (indicating less compensation for coarticulation) than individuals who produce greater coarticulatory nasality. However, in the ratings task, listeners’ produced nasal coarticulation did not predict perceptual patterns. Rather, more veridical perceptual response patterns were observed across participants in context-inappropriate coarticulatory conditions, i.e., for hypernasal vowels in C_N contexts (e.g. bẽ̃n) and nasal vowels in N_N contexts (e.g. mẽn). The results of this study suggest a complex and multifaceted relationship between representations used to produce and perceive speech.

Age and consonantal context effects on second language speech perception of French vowels

This study investigated the effects of age of acquisition (AOA) and consonantal contexts on second language (L2) speech perception of French vowel pairs /i/-/y/ and /y/-/u/. A total of 60 Korean learners of French participated in either an Early-AOA group (under 16 years), a Mid-AOA group (16-26 years), or a Late-AOA group (over 26 years). To measure their perceptual accuracy, AX categorical discrimination tasks were employed in which the two target pairs, in addition to a control pair /i/-/u/, were provided with three different consonants (i.e., /p/, /t/, and /k/) in a consonantal-vowel-consonantal structure. Overall, the Korean participants had more difficulty discriminating the pair /i/-/y/ than the pair /y/-/u/. In particular, the Korean participants revealed more difficulty with the former pair in the /p/ context, whereas they showed more difficulty with the latter pair in the /p/ and /t/ contexts. While those in the Early-AOA group significantly outperformed those in the Mid- and Late-AOA groups, those in the former group perceived the two target pairs in a way that was less affected by the consonantal contexts. Accordingly, this paper will conclude by highlighting the importance of AOA and consonantal contexts in L2 speech learning.

The acoustic counterpart to articulatory resistance and aggressiveness in locus equation metrics and vowel dispersion

Research on locus equation metrics (LEs) tend to take it for granted that vowel space is invariable across consonantal contexts. However, articulation-based studies report a mutual influence between neighboring segments such that segments with greater constraints in dorsal articulation are more resistant to and concurrently more aggressive in coarticulation than those with less constraints (Farnetani, 1990). We examine (1) whether articulatory resistance and aggressiveness can be acoustically captured through LEs and vowel dispersion and (2) how the relationship between LEs and the degree of coarticulation is mediated by vowel dispersion and delay in voicing. These questions are investigated in CV sequences in English –where C is one of /p t s ʃ/ that varies in the articulatory constraints imposed on the tongue dorsum. We manipulated the magnitude of coarticulation and voicing lag by contrastively stressing the target consonants. Our results show that there is a tight relationship between LE slopes and vowel dispersion where articulatory resistance and aggressiveness appear as the mirror image of each other in the acoustic signal. However, effects of hyperspeech simultaneously affect vowel dispersion, voicing delay, and LEs creating confounds. This calls for caution in the use of LE metrics as a measure of coarticulation.