A model of lingual coarticulation based on articulatory constraints

Abstract

The magnitude and temporal extent of consonantal and vocalic coarticulation are reported for VCV sequences with two vowels ͑/{/, /a/͒ and seven consonants ͑/!/, /'/, dark /(/, /2/, /b/, /F/,/%/͒. 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 /Fa/ 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 /!/ than when it is dark /(/͒. V-to-C effects are also conditioned by the tongue-dorsum position for the consonantal gesture. Coarticulatory directionality trends reveal that the extent to which the vowel-dependent tongue-dorsum activity may be anticipated is closely linked to the mechanico-inertial constraints associated with the tongue dorsum during consonantal production; this observation explains the salience of the vowel-dependent anticipatory effects in VCV sequences favoring C-to-V anticipation and of the vowel-dependent carryover effects in VCV sequences giving special weight to C-to-V carryover.

Timing of German onset and word boundary clusters

“…Sounds such as /n/ have been shown to have an intermediate resistance. They can exert influence on sounds that have an even lower resistance, such as bilabials, but they are influenced by sounds with a higher resistance (see Recasens et al 1997;Recasens 1999Recasens , 2012. If coarticulation results in place assimilation, this changes the paths from the preceding sounds to the target sound and from the target sound to the following sound.…”

“…According to Recasens' degree of articulatory constraint (DAC) model (e.g., Recasens et al 1997), sounds with a high "degree of involvement of the tongue dorsum in closure or constriction formation" (544), such as /s, ʃ, k/, exert much influence on the surrounding vowels (coarticulatory aggressiveness) and are themselves rather resistant to the influences of surrounding sounds (coarticulatory resistance).…”

Measuring lingual coarticulation from midsagittal tongue contours: Description and example calculations using English /t/ and /ɑ/

“…This supports the claim made by Ericsdotter et al about non-uniformity of vocalic coarticulatory effects on consonants. The distance between neighbouring segments can also inform us of the degree of gestural compatibility of these two segments, which was claimed by Recasens et al (1997) to affect the size of coarticulatory effects in speech. Recasens et al (1997) write that "a more accurate formulation of the articulatory constraints for consonants and vowels" (p. 545) could be used to improve the Degree of Articulatory Constraint model presented in their paper.…”

“…The measures used by Recasens et al (1997) allowed them to quantify consonantal influence on the vowel in symmetrical VCV sequences, by comparing the tongue-palate contact pattern at the middle of the vowel with the patterns in each EPG frame during the transition into the neighbouring consonant. The rationale behind this method of measurement was that C-on-V effects occur "during a period when a significant consonant-related acoustic or articulatory difference extends into the vowel" (Recasens et al 1997, p. 547).…”

“…Quantitative indices of lingual coarticulation based on articulatory results have been mostly designed for electropalatographic (EPG) data. Existing EPG-based indices are targeted at measuring, for example, the difference between overall tongue contact of a given phonetic segment in two different environments (Farnetani, 1990), the difference between two segments in location of the tongue-palate contact (Hardcastle et al 1991;Gibbon et al 1993) or the difference in behaviour of parts of the tongue (Recasens et al 1993;Fontdevila et al 1994;Recasens et al 1997).…”