Rhythmic variability between speakers: articulatory, prosodic, and linguistic factors

Area of Science:

• Phonetics
• Speech Science
• Linguistics

Background:

• Acoustically measurable speech rhythm exhibits variability.
• Understanding the sources of this variability, particularly between-speaker differences, is crucial for speech analysis.

Purpose of the Study:

• To investigate between-speaker variability in speech rhythm.
• To determine the impact of within-speaker variability (articulation rate, linguistic structure) on speech rhythm.

Main Methods:

• Analysis of speech rhythm metrics (%V, ΔV(ln), ΔC(ln), Δpeak(ln)) in Standard German and Zurich Swiss German speakers.
• Controlled manipulation of articulation rate (tempo conditions) and linguistic structure (spontaneous vs. read speech).
• Statistical analysis using repeated measures ANOVA to assess variability sources.

Main Results:

• Strong and consistent between-speaker variability in speech rhythm was observed.
• Within-speaker variability due to articulation rate and linguistic characteristics was generally not significant.
• Speech rhythm differences between speakers were robust against variations in speaking rate and linguistic complexity.

Conclusions:

• Between-speaker variability in speech rhythm is a dominant and stable characteristic.
• Idiosyncratic articulatory movements are the most likely cause of persistent between-speaker differences in speech rhythm.
• Speech rhythm is a reliable indicator of individual speaker characteristics.