Voice onset time in normal-aged population

Area of Science:

• Speech production and acoustics
• Gerontology
• Linguistics

Background:

• Aging affects fine motor skills, potentially impacting speech production.
• Voice onset time (VOT) measures articulatory-laryngeal adjustments.
• Understanding age-related speech changes is crucial for temporal speech control models.

Purpose of the Study:

• To investigate age-related changes in voice onset time (VOT).
• To extend the temporal speech control model to elderly populations.
• To analyze VOT variability and phonemic boundary shifts in aging adults.

Main Methods:

• Descriptive study comparing VOT across three age groups (25-39, 65-74, 75+).
• Analysis of 30 tokens per subject for words 'beat', 'pete', 'bead' using wide-band spectrograms.
• Statistical analysis of VOT means, standard deviations, and phonemic boundary separation.

Main Results:

• Mean VOT did not significantly differ across age groups.
• VOT variability (standard deviation) significantly increased with age.
• Minimal separation between /b/ and /p/ phonemic boundaries decreased significantly with aging.

Conclusions:

• While mean VOT remains stable, speech motor control exhibits increased variability in older adults.
• Aging leads to reduced perceptual distinctiveness between voiced and voiceless bilabial stops (/b/ vs. /p/).
• Findings suggest age-related modifications in the neural control of speech timing.