Toward phonetically grounded distinctive features. Part I: Acoustic-articulatory correlations in a four-region model of the vocal tract
Main Article Content
Abstract
The purpose of this paper is to correlate the four formant frequencies F1–F4 and quality factors Q1–Q4 with the positions, areas, or area ratios formed by the four active articulators: tongue
root, tongue body, blade, and lips. The quality or amplification factor Q is the formant frequency F divided by the bandwidth B. Toward this end, a 27-tube frequency-domain vocal tract model (FDVT)
is developed. Four articulator regions are delimited in the model: an 8-tube tongue root region, a 9-tube tongue body region (one-quarter wavelength of F2), a 6-tube blade region (one-quarter
wavelength of F3), and a 4-tube lip region. Vowel area functions of ten speakers were taken from seven X-ray and MRI studies and fit to 27 equal-length tubes using cubic spline interpolation.
Correlation matrices between the acoustic and articulatory parameters are calculated for the vowel system of each speaker. The coefficients of the parameter pairs are averaged across the ten speakers
and the most highly correlated ones are ranked. Tongue root aperture (tongue root area normalized by lip area) is shown to be inversely correlated with F1 frequency. When the tongue body and blade
constrictions move toward the lips through their respective one-quarter wavelengths, the F2 and F3 frequencies also shift higher. Tongue body aperture (tongue body area normalized by lip area) is directly correlated with Q2. Similarly, blade aperture (blade area normalized by lip area) is directly correlated with Q3. Lip protrusion displays an inverse correlation with F4 frequency. Lip aperture (lip
area) has a moderate direct correlation with F1 and a weaker inverse correlation with Q4. In agreement with perturbation analysis, F1 frequency is found to be closely correlated with the tongue
root area, but negligibly correlated with the tongue body area. Consequently, F1 distinctions among high, mid, and low vowels are made by varying the tongue root aperture and not, as is traditionally
assumed, by raising or lowering the tongue body.
Downloads
Article Details
The Indiana University Linguistics Club Working Papers (the "Publisher") and Author(s) agree as follows.
1. Publication and Promotion: In consideration of the Publisher's agreement to publish the Work, Author hereby grants and assigns to Publisher the non-exclusive right to print, publish, reproduce, or distribute the Work throughout the world in all means of expression by any method known or hereafter developed, including electronic format. Author further grants Publisher the right to use Author's name in association with the Work in published form and in advertising and promotional materials.
2. Copyright: Copyright of the Work remains in the Author's name.
3. Prior Publication and Attribution: Author agrees not to publish the Work in print form prior to publication of the Work by the Publisher. Author agrees to notify IULCWP before publishing the Work elsewhere.
4. Author Representations: The Author represents and warrants that the Work: (a) is the Author's original Work and that the Author has full power to enter into this Agreement; (b) does not infringe the copyright or property of another; (c) contains no material that is obscene, libelous, or defamatory. Author shall indemnify and hold Publisher harmless against loss of expenses arising from breach of any such warranties.
5. Licensing and Reuse: Reuse of the published Work will be governed by a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY https://creativecommons.org/licenses/by-nc/4.0/ ). This lets others remix, tweak, and build upon the Work non-commercially; although new works must acknowledge the original IULCWP publication and be non-commercial, they do not have to be licensed on the same terms.