Anticipatory coarticulation: some implications from a study of lip rounding

Area of Science:

• Phonetics and Speech Science
• Articulatory Phonology
• Motor Control in Speech

Background:

• Articulatory features, such as lip rounding, can be anticipated.
• Previous research suggests anticipation can occur up to four segments prior to the target vowel.
• Understanding the precise timing and triggers of articulatory anticipation is crucial for speech production models.

Purpose of the Study:

• To investigate the precise timing of motor commands for lip rounding.
• To determine if the timing of lip rounding anticipation is influenced by preceding consonant segments.
• To explore the relationship between lip rounding initiation and other vowel articulation features.

Main Methods:

• Analysis of motor commands related to the lip rounding gesture for the vowel /u/.
• Measurement of the onset of rounding commands relative to vowel onset.
• Experimental manipulation of the number of consonant segments preceding the target vowel.

Main Results:

• Motor commands for lip rounding for /u/ initiate at a fixed time before the vowel onset.
• This fixed timing is independent of the number of consonant segments in the preceding phonetic string.
• The data indicate a consistent temporal pattern in the initiation of the rounding gesture.

Conclusions:

• The initiation of lip rounding is triggered by a fixed temporal cue.
• This timing is not directly dependent on the complexity of the preceding consonantal context.
• Lip rounding anticipation appears to be intrinsically linked to other aspects of vowel articulation.