Quantifying lingual coarticulation in German using mutual information: An ultrasound study

Area of Science:

• Linguistics
• Speech Science
• Phonetics

Background:

• Mutual information (MI) previously quantified information between phonological segments using electromagnetic articulography.
• Coarticulation quantification methods vary across data collection techniques.

Purpose of the Study:

• Extend mutual information (MI) to quantify coarticulatory resistance (CR) and overlap in German.
• Evaluate two distinct articulatory measurements as input for MI analysis.
• Examine temporal changes in coarticulation during syllable production.

Main Methods:

• Utilized ultrasound imaging to capture tongue movements during speech production.
• Applied mutual information (MI) analysis to two sets of articulatory data: highest tongue body point and first DFT coefficient of tongue contour.
• Analyzed coarticulation at consonant midpoint and vowel onset time points within syllables.

Main Results:

• Corroborated existing findings on differences in coarticulatory overlap across languages.
• The highest tongue body point measure effectively captured distinctions in place and manner of articulation.
• The first DFT coefficient did not offer additional insights into global coarticulatory resistance (CR).
• Both MI input measures successfully identified temporal distinctions in coarticulatory resistance.

Conclusions:

• Mutual information (MI) is a viable method for quantifying coarticulatory resistance (CR) and overlap.
• The highest tongue body point provides a more informative measure for articulatory analysis than the first DFT coefficient.
• MI offers a potential framework for unifying coarticulation quantification across different data acquisition methods.