Variability in word duration as a function of probability, speech style, and prosody

Area of Science:

• Linguistics
• Phonetics
• Speech Science

Background:

• Word duration is influenced by various linguistic and phonetic factors.
• Understanding the interplay between probability, speech style, and prosody is crucial for speech production models.

Purpose of the Study:

• To investigate the effects of probability (lexical frequency, previous mention), speech style (clear, plain), and prosody on word duration.
• To examine the interactions between these factors in spoken language.

Main Methods:

• Participants read controlled materials in both clear and plain speech styles.
• Acoustic analysis was used to measure word duration.
• Statistical analysis was performed to assess the significance of different factors and their interactions.

Main Results:

• More probable words (higher frequency, second mention) were significantly shorter.
• Words in plain speech were shorter than in clear speech, especially for lexical frequency.
• Second mention reduction occurred in both speech styles, indicating probability effects persist even with hyper-articulation.
• An interaction between mention and frequency in plain speech showed high-frequency words allowed more reduction.

Conclusions:

• Word probability, particularly lexical frequency and prior mention, directly influences word duration.
• While clear speech involves hyper-articulation, probabilistic effects on duration are not overridden.
• Speech production balances probabilistic predictability with articulatory effort, showing a tendency towards hypo-articulation when factors align.