Daniel Recasens

A model of lingual coarticulation based on articulatory constraints

The magnitude and temporal extent of consonantal and vocalic coarticulation are reported for VCV sequences with two vowels (/i/, /a/) and seven consonants (/p/, /n/, dark /l/, /s/, /∫/, /ɲ/,/k/). Different degrees of articulatory constraint, or DAC values, are assigned to the consonants and vowels based on knowledge of their articulatory properties, in particular, the degree of involvement of the tongue dorsum in closure or constriction formation. Mean results on dorsopalatal contact and F2 frequency for five speakers of the Catalan language are presented. Predictions based on the DAC value for consonants and vowels account satisfactorily for the C-to-V effects (e.g., those for /ɲa/ are more prominent that those for /pi/); moreover, vowel-dependent effects tend to be negatively correlated with the DAC value for the consonant (e.g., they are more prominent when the intervocalic consonant is /p/ than when it is dark /l/). V-to-C effects are also conditioned by the tongue-dorsum position for the consonantal ...

Vowel‐to‐vowel coarticulation in Catalan VCV sequences

Electropalatographic and acoustical data on vowel-to-vowel (V-to-V) coarticulatory effects were obtained for Catalan VCV sequences, with the consonants representing different degrees of tongue-dorsum contact (dorsopalatal approximant [j], alveolo-palatal nasal [eta], alveolo-palatal lateral [lambda], and alveolar nasal [n]). Results show that the degree of V-to-V coarticulation in linguopalatal fronting and F2 frequency varies monotonically and inversely with the degree of tongue-dorsum contact, carryover effects being larger than anticipatory effects. The temporal extent of coarticulation also varies with the degree of tongue-dorsum contact, much more so for anticipatory effects than for carryover effects. Overall, results indicate that V-to-V coarticulation in VCV sequences is dependent on the mechanical constraints imposed on the tongue dorsum to achieve dorsopalatal closure during the production of the intervening consonant. Moreover, anticipatory effects, but not carryover effects, involve articulatory preprogramming.

Coarticulatory patterns and degrees of coarticulatory resistance in Catalan CV sequences.

This paper is an extensive acoustic analysis of V-to-C and C-to-V coarticulatory effects in Catalan CV sequences for 18 consonants and 8 vowels. Data indicate that Catalan phonemes differ as to the degree of resistance to coarticulation and suggest strongly that differences in coarticulatory resistance follow from differences in degree of articulatory constraint. A theory of coarticulation is proposed that accounts for coarticulatory effects in terms of the articulatory constraints involved in the production of gestures for adjacent phonemes, indeperdently of considerations about the linguistic nature of the phonemic units under control. It is argued that such a theory is more likely to explain patterns of coarticulatory activity arising from compatible and conflicting gestures than previous coarticulation models.

Articulatory, positional and coarticulatory characteristics for clear /l/ and dark /l/ : evidence from two Catalan dialects

Electropalatographic and acoustic data reported in this study show differences in closure location and degree, dorsopalatal contact size, closure duration, relative timing of events and formant frequency between clear /l/ and dark /l/ in two dialects of Catalan (Valencian and Majorcan). The two Catalan dialects under investigation differ also regarding degree of darkness but essentially not regarding coarticulatory resistance at the word edges, i.e. the alveolar lateral is equally dark word-initially and word-finally in Majorcan, and clearer in the former position vs. than the latter in Valencian, and more resistant to vowel effects in the two positions than intervocalically in both dialects. With reference to data from the literature, it appears that languages and dialects may differ as to whether /l/ is dark or clear in all word positions or whether or not initial /l/ is clearer than final /l/, and that articulatory strengthening occurs not only word- and utterance-initially but word- and utterance-finally as well. These and other considerations confirm the hypothesis that degree of darkness in /l/ proceeds gradually rather than categorically from one language to another.

An articulatory investigation of lingual coarticulatory resistance and aggressiveness for consonants and vowels in Catalan.

Lingual movement data for Catalan vowel-consonant-vowel sequences reveal differences in contextual coarticulatory variability in tongue position at the middle of the consonant for p>/n/>dark/l/>/s/>> and at vowel midpoint for /u/>/a/>/i/. The velar stop /k/ exhibits a high degree of contextual variability in the horizontal dimension but not in the vertical dimension. These differences in coarticulatory sensitivity are attributed to differences in articulatory constraint, e.g., palatality and frication cause a higher degree of resistance in the consonant than laterality. A higher degree of contextual variability for dark /l/ than expected appears to be associated with speaker-dependent differences in darkness degree. Contextual variability is greater at regions not involved in closure or constriction formation, e.g., at the tongue dorsum than at the tongue front for alveolars. Coarticulatory resistance and coarticulatory aggressiveness are positively correlated: Phonetic segments, which are especially resistant to coarticulatory effects from the adjacent segments, exert maximal coarticulation on them. Consequently, highly constrained segments such as alveolopalatal consonants turn out to affect tongue position for less constrained segments such as back vowels rather than vice versa.

An EMA study of VCV coarticulatory direction

This study addresses three issues that are relevant to coarticulation theory in speech production: whether the degree of articulatory constraint model (DAC model) accounts for patterns of the directionality of tongue dorsum coarticulatory influences; the extent to which those patterns in tongue dorsum coarticulatory direction are similar to those for the tongue tip; and whether speech motor control and phonemic planning use a fixed or a context-dependent temporal window. Tongue dorsum and tongue tip movement data on vowel-to-vowel coarticulation are reported for Catalan VCV sequences with vowels /i/, /a/, and /u/, and consonants /p/, /n/, dark /l/, /s/, /S/, alveolopalatal /n/ and /k/. Electromidsagittal articulometry recordings were carried out for three speakers using the Carstens articulograph. Trajectory data are presented for the vertical dimension for the tongue dorsum, and for the horizontal dimension for tongue dorsum and tip. In agreement with predictions of the DAC model, results show that directionality patterns of tongue dorsum coarticulation can be accounted for to a large extent based on the articulatory requirements on consonantal production. While dorsals exhibit analogous trends in coarticulatory direction for all articulators and articulatory dimensions, this is mostly so for the tongue dorsum and tip along the horizontal dimension in the case of lingual fricatives and apicolaminal consonants. This finding results from different articulatory strategies: while dorsal consonants are implemented through homogeneous tongue body activation, the tongue tip and tongue dorsum act more independently for more anterior consonantal productions. Discontinuous coarticulatory effects reported in the present investigation suggest that phonemic planning is adaptative rather than context independent.

Place cues for nasal consonants with special reference to Catalan

This study investigates the perceptual contributions of formant transitions and nasal murmurs to the identification of the unreleased Catalan nasal consonants [n], [n], [n] (alveolar, palatal, velar, respectively) after [a] in absolute final position. Transition and murmur patterns were synthesized and varied simultaneously and systematically by interpolating between optimal values obtained from spectrographic analysis of natural speech. Catalan subjects were asked to identify the synthetic stimuli as [n], [n], and [n]. The main findings were: (1) Although transitions provided more effective cues for place of articulation than murmurs, the murmurs did make a significant contribution to the [n]-[n] distinction. (2) The cue value of the transitions ([n] greater than [n], [n]) was inversely related to that of the murmurs ([n], [n] greater than [n]). It is concluded that static and dynamic place cues for nasals in an [aC#] context are perceptually integrated with reference to the typical pattern of production of these consonants.

Dispersion and variability of Catalan vowels

Formant frequency data for Catalan vowels reveal essentially the same degree of expansion for three dialect systems with seven vowels (Valencian, Eastern Catalan, Western Catalan). A slightly larger vowel space dispersion for a fourth system with those same vowels and stressed /c/ (Majorcan) is not clearly associated with a larger vowel system size but rather with a local effect of schwa in repelling neighbouring vowels or with specific requirements on the production of some peripheral vowels. Schwa appears to be targetless or specified for a widely defined mid central target. Intervocalic distances were found to vary according to dialect and to vowel pair, and to compensate with each other such that the maximal formant frequency range between point vowels is kept constant across dialects. These findings are partially in support of the Adaptive Dispersion Theory, i.e., they are in agreement with the claim that vowel system expansion should be proportional to vowel system size but not with the notion that adjacent vowels should be evenly spaced in identical vowel systems. Patterns of vowel variability differ depending on the contextual or non-contextual factors involved, i.e., F1 shows more contextual and token-to-token variation for open vs. close vowels, while F2 exhibits little contextual variation and much token-dependent variation for /i/ and the opposite trend for /u/ and /c/. These patterns are accounted for assuming that random variability for vowels is ruled by the precision involved in achieving a specific articulatory target, and that contextual variability is determined by the vowel articulatory requirements and by the relative compatibility between the articulatory gestures for adjacent vowels and consonants. � 2005 Elsevier B.V. All rights reserved.

Coarticulation, assimilation and blending in Catalan consonant clusters

Abstract Electropalatographic data on C-to-C coarticulatory effects were analyzed for consonant clusters composed of an extensive set of Catalan consonants, i.e., dentals (t), alveolars (n, dark l, s, trilledr ), alveolopalatals (∫, ⋌ n), palatals (j) and velars (k). Regarding tongue dorsum coarticulation, results show that consonantal effects in CC clusters are more prominent than vocalic effects in VCV sequences which is attributed to differences in articulatory control between consonants and vowels. Moreover, tongue dorsum lowering for the alveolar fricative and for the alveolar trill appears to be more coarticulation resistant than tongue dorsum raising and fronting for alveolopalatals. Data at the place of articulation show some interesting trends: on the one hand, sequences made of dentals (t), and fronter alveolars and alveolopalatals (i.e., n, l, ⋌, n) yield articulatory blending; on the other hand, any of these consonants may assimilate to those alveolar and alveolopalatal consonants which exhibit a more retracted place of articulation (s, r, ∫), but not vice versa. These findings are in agreement with the “degree of articulatory constraint” (DAC) model which relates coarticulatory and assimilatory effects to the degree of articulatory constraint involved in consonantal production, and predicts that fricatives and trills should be highly constrained both at the tongue front and at the tongue dorsum. Data on the relative strength of the anticipatory and carry-over effects reported in this paper are also to a large extent in agreement with predictions of the DAC model.

Darkness in [l] as a scalar phonetic property: implications for phonology and articulatory control

Dorsopalatal contact and F2 data for speakers of dialectal groups with dark [l] (Majorcan Catalan, Eastern Catalan) and clear [l] (German, Catalan from the València region) provide some support for the hypothesis that degree of velarization or pharyngealization in the alveolar lateral consonant does not proceed categorically but gradually across dialects. Indeed, F2 frequency data for [l] in the context of [i] reveal that darkness does not distinguish the two dialectal groups but varies gradually from dialects with a very dark realization of [l] (Mallorquí) to those with a very clear realization (Valencià) through dialects exhibiting intermediate degrees of darkness (Eastern Catalan, German). A similar scenario applies to the [a] context. This finding questions the complex, two‐gestural status of dark [l] and the notion that dark [l] should always be more coarticulation resistant than clear [l].