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Published on: December 2, 2011
A statistical, formant-pattern model for segregating vowel type and vocal-tract length in developmental formant data.
Richard E Turner1, Thomas C Walters, Jessica J M Monaghan
1Gatsby Computational Neuroscience Unit, Alexandra House, 17 Queen Square, London, United Kingdom. turner@gatsby.ucl.ac.uk
The Journal of the Acoustical Society of America
|April 10, 2009
Summary
This study models vocal tract length (VTL) using formant frequencies. Results show VTL significantly impacts vowel sounds, aiding accurate VTL estimation in speech development research.
Area of Science:
- Acoustic phonetics
- Speech science
- Linguistics
Background:
- Vocal tract length (VTL) influences speech acoustics.
- Estimating VTL from formant frequencies is crucial for understanding speech development.
- Previous models have limitations in accounting for developmental changes.
Purpose of the Study:
- To develop a statistical inference model for estimating VTL from formant frequencies.
- To investigate the relationship between vowel type, VTL, and vocal cavity size.
- To analyze developmental changes in VTL and their impact on speech acoustics.
Main Methods:
- Developed a statistical inference model linking vowel type and VTL to formant frequencies.
- Applied the model to existing developmental formant frequency datasets.
- Estimated VTLs and analyzed their relationship with glottal pulse rate during maturation.
Main Results:
- VTL is a primary source of formant frequency variability, secondary only to vowel type.
- Developmental changes in oral-pharyngeal ratio have a minor impact compared to measurement noise.
- Speakers adjust vocal tract shape during growth to maintain vowel-specific formant patterns.
Conclusions:
- The developed statistical model accurately estimates VTL from formant frequencies.
- VTL estimation provides a refined understanding of VTL-glottal pulse rate dynamics in maturing children.
- Findings support the formant-pattern hypothesis, suggesting vocal tract shape adjustments during development.
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