Low mach number flow through a constricted, stylized vocal tract

Ongoing research intended to contribute to the development of compact descriptions of the information in the human speech signal is described. This paper presents an early progress report on work which focuses on one aspect of this research - characterization of voiceless-fricative generation. A stylized dental fricative topology, with features representative of the vocal tract geometry for the phoneme /s/ (as in sun), has been developed. The flow, acoustic source terms, and acoustic spectra for this topology are being evaluated using experimental, traditional computational fluid dynamic, and computational aeroacoustic approaches. For each approach, mean flow quantities, turbulence intensities and acoustic spectra are being measured or computed. The experimental approach has been designed so that a high quality data set will be available for detailed comparison with both computational approaches. The use of two computational methods will allow assessment of the limitations/benefits of each approach through computational comparisons and comparison with the experimental data.