Stop place coding: an acoustic study of CV, VC#, and C#V sequences

Area of Science:

• Phonetics
• Speech Science
• Acoustic Phonetics

Background:

• Understanding how speech sounds are produced and perceived is crucial for fields like linguistics and audiology.
• Stop consonant place of articulation is a key feature differentiating meaning in many languages.
• Coarticulation, the influence of adjacent sounds on a speech sound, plays a significant role in speech perception and production.

Purpose of the Study:

• To investigate stop + vowel coarticulation as a mechanism for differentiating stop place categories.
• To examine the utility of locus equations (LEs) in indexing coarticulation across different speech contexts.
• To compare coarticulation patterns in onset, coda, and across-syllable/word boundary conditions.

Main Methods:

• Utilized locus equations (LEs) to quantify coarticulation in stop + vowel utterances.
• Analyzed three contexts: onset stop + vowel [.CV], within-syllable vowel + coda stop [VC#], and across-syllable/word coda stop + vowel [C#V].
• Recorded and analyzed tokens produced by speakers of American English and Persian, including voiced labial, alveolar/dental, and velar stops.

Main Results:

• Anticipatory coarticulation was reduced in the across-syllable/word boundary [C#V2] condition compared to onset [CV2] syllables.
• Despite reduced coarticulation, LE slopes across the syllable/word boundary still differentiated stop places.
• LE slopes derived from within-syllable [V1C#] sequences did not show significant differences between stop places.

Conclusions:

• Stop place of articulation can be distinguished through coarticulation patterns, even across word boundaries.
• Locus equations are effective in indexing coarticulation and differentiating stop places in various speech contexts.
• The findings contribute to understanding the acoustic coding of phonetic information in continuous speech.