Comparison of Fricative Vocal Tract Transfer Functions Derived using Two Different Segmentation Techniques

Authors: K. S. Subari, C. H. Shadle, A. Barney, R. I. Damper

Abstract:

The acoustic and articulatory properties of fricative speech sounds are being studied using magnetic resonance imaging (MRI) and acoustic recordings from a single subject. Area functions were derived from a complete set of axial and coronal MR slices using two different methods: the Mermelstein technique and the Blum transform. Area functions derived from the two techniques were shown to differ significantly in some cases. Such differences will lead to different acoustic predictions and it is important to know which is the more accurate. The vocal tract acoustic transfer function (VTTF) was derived from these area functions for each fricative and compared with measured speech signals for the same fricative and same subject. The VTTFs for /f/ in two vowel contexts and the corresponding acoustic spectra are derived here; the Blum transform appears to show a better match between prediction and measurement than the Mermelstein technique.

Keywords: Area functions, fricatives, vocal tract transferfunction, MRI, speech.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1077197

References:

[1] Able Software Corp., http://www.ablesw.com/3d-doctor/.
[2] H. Blum, "Biological shape and visual science: Part 1," Journal of Theoretical Biology, vol. 38, pp. 205-287, 1973.
[3] C. Coker and O. Fujimura, "Model for specification of the vocal tract area function," Journal of the Acoustical Society of America, vol. 40, pp. 1271, 1966 (abstract).
[4] P. O. A. L. Davies, R. S. McGowan and C. H. Shadle, "Practical flow duct acoustics applied to the vocal tract," in Vocal Fold Physiology: Frontiers in Basic Science, 1st ed. R. Titze, Ed. Singular Publishers, San Diego, CA, 1993, pp. 93-142.
[5] J. L. Flanagan and L. Cherry, "Excitation of vocal tract synthesizers," Journal of the Acoustical Society of America, vol. 45, no. 3, pp. 764-769, 1969.
[6] U. G. Goldstein, "An Articulatory Model for the Vocal Tracts of Growing Children," PhD dissertation, Department of Electrical Engineering and Computer Science, MIT, Cambridge, MA, 1980.
[7] P. J. B. Jackson, "Characterisation of Plosive, Fricative and Aspiration Components in Speech Production," PhD dissertation, Department of Electronics and Computer Science, University of Southampton, UK, 2000.
[8] P. Mermelstein, "Articulatory model for the study of speech production," Journal of the Acoustical Society of America, vol. 53, no. 4, pp. 1070-1082, 1973.
[9] C. H. Shadle, M. Tiede, S. Masaki, Y. Shimada and I. Fujimoto, "An MRI study of the effects of vowel context on fricatives," Proceedings of the Institute of Acoustics, vol. 18, no. 9, pp. 187-193, 1996.