Bridging planning and execution: Temporal planning of syllables

Area of Science:

• Linguistics
• Speech Science
• Phonetics

Background:

• Understanding word initiation time is crucial for speech production models.
• Syllable structure complexity may influence the temporal planning of speech.
• Previous research has explored acoustic measures, but articulatory data offers a more direct insight into motor planning.

Purpose of the Study:

• To investigate the hypothesis that different syllable structures require varying preparation times for temporal control.
• To compare word initiation times based on acoustic and articulatory measurements across different syllable structures.
• To examine the influence of initial segments and coda presence on word initiation timing.

Main Methods:

• Two delayed naming experiments were conducted.
• Experiment 1: Initiation time measured from acoustic recordings.
• Experiment 2: Speech movements (tongue, jaw, lips) recorded using electromagnetic articulography to measure initiation time from articulatory data.

Main Results:

• Acoustic analysis confirmed the hypothesis, showing interactions with initial segments (vowel-initial words slower, especially with /l/ or /s/ onsets).
• Adding a coda did not significantly affect acoustic initiation time.
• Articulatory measurements revealed a significant effect of syllable structure, with vowel-consonant (VC) words initiated later than consonant-vowel (CV) or consonant-vowel-consonant (CVC) words.
• Articulatory data showed only minor effects of the initial segment.

Conclusions:

• Syllable structure significantly impacts speech initiation timing, particularly evident in articulatory planning.
• The findings suggest that the complexity of articulatory gesture coordination and timing contributes to initiation time differences.
• Speaker experience in coordinating gesture combinations may play a role in speech timing.