One-dimensional and three-dimensional propagation analyses of acoustic characteristics of Japanese and French vowel /a/ with nasal coupling

Abstract

In this paper, we describe a comparison of the acoustic characteristics of one-dimensional and three-dimensional models of vocal tracts with nasal coupling. One-dimensional acoustic propagation is computed using an electric analog model. A finite element method is used for threedimensional acoustic simulation. The comparison of these two approaches involves the vocal-tract shape of two subjects, one Japanese male and one French male pronouncing the vowel /a/ in their native language. Results show that the pole/zero pairs ascribed to the nasal coupling for both simulations appeared at almost the same frequency, at least below 2 kHz. Little difference between the one-dimensional and three-dimensional simulations in the transfer functions for the French subject is observed, since the three-dimensional mesh for the French subject is smoother. An extra pole exists in the transfer function of the three-dimensional model for the Japanese subject, possibly caused by the asymmetric structure of the laryngeal cavity. In the three-dimensional distribution of the active sound intensity vectors for the French subject, sound energy fluxes circulate between oral and nasal cavities coupled in the vicinity of the lips and nostrils.

Data-glove-driven vocal tract configuration methods for vowel synthesis

“…However, one-dimensional model of the vocal tract, i.e., an acoustic tube model, can be a simple but effective model of the vocal tract. Indeed, it is reported that the acoustic characteristics of the one-dimensional model are similar to those of a three-dimensional model at lower frequencies [7].…”

“…An original vocal tract has a complicated shape [7], making it difficult to mimic its shape and behavior using a data glove. However, one-dimensional model of the vocal tract, i.e., an acoustic tube model, can be a simple but effective model of the vocal tract.…”

Tuning of vocal tract model parameters for nasals using sensitivity functions

“…The types of models range from parametric models (e.g., Badin et al, 2005), tube or transmission-line models (e.g., Flanagan, 1972;Kelly and Lochbaum, 1962;Lim and Lee, 1993;Markel and Gray, 1976) to more elaborated wave guide and (3D)-FEM/BEM models (e.g., Matsuzaki et al, 2014).…”

Finite element analysis of fine-structural effect on acoustic characteristics of vocal tract

“…For a three-dimensional (3-D) vocal-tract model based on magnetic resonance imaging (MRI) data, many extra poles in addition to formants and zeros are observed in vocal-tract transfer functions (VTTFs) [1]. Dang and Honda reported that the piriform fossa contributes strong troughs to the VTTFs, as determined from measurement experiments using an MRIbased mechanical model [2].…”

“…1. This model is constructed on the basis of vowel MRI data of the Japanese /a/ of an adult male [1]. As seen from the front view, a curved constriction indicated by an arrow is formed in the laryngeal cavity.…”