FIXED TEMPORAL PATTERNS IN CHILDREN'S SPEECH DESPITE VARIABLE VOWEL DURATIONS.

Area of Science:

• Speech production
• Developmental linguistics
• Phonetics

Background:

• Vowel duration is crucial for speech intelligibility.
• Understanding age-related differences in speech timing is important for developmental studies.
• Previous research suggests children may struggle with precise motor control in speech.

Purpose of the Study:

• To compare children's and adults' ability to produce inherent and context-specific vowel duration differences.
• To assess children's and adults' ability to repeatedly produce the same vowel in the same context.
• To analyze vowel duration and variability in relation to age and context.

Main Methods:

• Participants (5- and 8-year-old children and adults) produced real English words in a frame sentence repeatedly.
• Acoustic analysis of mean vowel duration and vowel duration variability was performed.
• Data were analyzed as a function of manipulated factors including age and phonetic context.

Main Results:

• Children demonstrated the ability to produce the same vowel duration contrasts as adults.
• Children exhibited greater variability in the production of individual vowels compared to adults.
• Both age groups successfully produced inherent and context-specific vowel duration differences.

Conclusions:

• Children's speech production systems can accurately represent and execute relative timing information for vowel contrasts.
• Increased variability in children's speech production does not impede their ability to produce phonemic contrasts.
• Findings support a model where speech production relies on remembered relative timing (the 'plan') and motor execution of temporal goals.