Study of acoustic characteristics of vocal tract with nasal cavity during phonation of Japanese /a/

Matsuzaki, Hiroyuki; Motoki, Kunitoshi

doi:10.1250/ast.28.124

Cited by 11 publications

(20 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the 3-D distribution of the active sound intensity vectors at F2 for the French subject, a flow of the sound energy flux from the nostrils to the top of the pharynx is also observed, which is similar to the results for the Japanese subject [11].…”

Section: Discussionsupporting

confidence: 82%

“…Note that this nasal coupling is observed for a specific subject [11,13], although ordinary Japanese vowels do not include nasalized vowels. This study also includes an acoustic comparison between the French and Japanese /a/ with nasal coupling.…”

Section: Introductionmentioning

confidence: 98%

“…Moreover, acoustic characteristics of three-dimensional (3-D) nasal tracts [7][8][9] and vocal tracts with nasal coupling [10,11] have also been studied by a finite element method (FEM).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

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

Matsuzaki

Serrurier

Badin

et al. 2014

Acoust. Sci. & Tech.

Self Cite

View full text Add to dashboard Cite

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.

show abstract

Section: Discussionsupporting

confidence: 82%

Section: Introductionmentioning

confidence: 98%

See 1 more Smart Citation

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

Matsuzaki

Serrurier

Badin

et al. 2014

Acoust. Sci. & Tech.

Self Cite

View full text Add to dashboard Cite

show abstract

“…For example, the following has been reported using these analyses: there is no significant difference between the finite element method and the boundary element method in the comparison of acoustic analyses of the vocal tract 4 ; and the presence of a pole-zero pair, which is a characteristic of a nasalized vowel, is confirmed as a result of acoustic analysis including the nasal cavity. 5 However, in these reports, the first formant (F1) and the second formant (F2) calculated from the analysis have diverged considerably from the F1 and F2 obtained from the actual voice. 4,5 Therefore, the aim was to simulate and visualize the relationship between the vocal tract and the sound produced there, that is, the form of the vocal tract and the voice, by applying acoustic analysis using the boundary element method to the articulatory organ, and then to clarify the pathogenesis of articulation disorders.…”

Section: Introductionmentioning

confidence: 87%

“…5 However, in these reports, the first formant (F1) and the second formant (F2) calculated from the analysis have diverged considerably from the F1 and F2 obtained from the actual voice. 4,5 Therefore, the aim was to simulate and visualize the relationship between the vocal tract and the sound produced there, that is, the form of the vocal tract and the voice, by applying acoustic analysis using the boundary element method to the articulatory organ, and then to clarify the pathogenesis of articulation disorders. The purposes of this study were to establish an acoustic simulation of the vocal tract and to verify the validity of the simulation.…”

Section: Introductionmentioning

confidence: 87%

Development of an Acoustic Simulation Method during Phonation of the Japanese Vowel /a/ by the Boundary Element Method

2021

View full text Add to dashboard Cite

The purpose of the present study was to establish the method for an acoustic simulation of a vocal tract created from CT data during phonation of the Japanese vowel /a/ and to verify the validity of the simulation. Material and methods. The subjects were 15 healthy adults (8 males, 7 females). The vocal tract model was created from CT data acquired during sustained phonation of the Japanese vowel /a/. After conversion to a mesh model for analysis, a wave acoustic analysis was performed with a boundary element method. The wall and the bottom of the vocal tract model were regarded as a rigid wall and a nonrigid wall, respectively. The acoustic medium was set to 37°C, and a point sound source was set in the place corresponding to the vocal cord as a sound source. The first and second formant frequencies (F1 and F2) were calculated. For 1 of the 15 subjects, the range from the upper end of the frontal sinus to the tracheal bifurcation was scanned, and 2 models were created: model 1 included the range from the frontal sinus to the tracheal bifurcation; and model 2 included the range from the frontal sinus to the glottis and added a virtually extended trachea by 12 cm cylindrically. F1 and F2 calculated from models 1 and 2 were compared. To evaluate the validity of the present simulation, F1 and F2 calculated from the simulation were compared with those of the actual voice and the sound generated using a solid model and a whistle-type artificial larynx. To judge the validity, the vowel formant frequency discrimination threshold reported in the past was used as a criterion. Namely, the relative discrimination thresholds (%), dividing 4F by F, where F was the formant frequency calculated from the simulation, and 4F was the difference between F and the formant frequency of the actual voice and the sound generated using the solid model and artificial larynx, were obtained. Results. F1 and F2 calculated from models 1 and 2 were similar. Therefore, to reduce the exposure dose, the remaining 14 subjects were scanned from the upper end of the frontal sinus to the glottis, and model 2 with the trachea extended by 12 cm virtually was used for the simulation. The averages of the relative discrimination thresholds against F1 and F2 calculated from the actual voice were 5.9% and 4.6%, respectively. The averages of the relative discrimination thresholds against F1 and F2 calculated from the sound generated by using the solid model and the artificial larynx were 4.1% and 3.7%, respectively. Conclusions. The Japanese vowel /a/ could be simulated with high validity for the vocal tract models created from the CT data during phonation of /a/ using the boundary element method.

show abstract

Formant frequencies and bandwidths of the vocal tract transfer function are affected by the mechanical impedance of the vocal tract wall

Fleischer

Pinkert

Mattheus

et al. 2014

Biomech Model Mechanobiol

View full text Add to dashboard Cite

The acoustical properties of the vocal tract, the air-filled cavity between the vocal folds and the mouth opening, are determined by its individual geometry, the physical properties of the air and of its boundaries. In this article, we address the necessity of complex impedance boundary conditions at the mouth opening and at the border of the acoustical domain inside the human vocal tract. Using finite element models based on MRI data for spoken and sung vowels /a/, /i/ and // and comparison of the transfer characteristics by analysis of acoustical data using an inverse filtering method, the global wall impedance showed a frequency-dependent behaviour and depends on the produced vowel and therefore on the individual vocal tract geometry. The values of the normalised inertial component (represented by the imaginary part of the impedance) ranged from at frequencies higher than about 3 kHz up to about in the mid-frequency range around 1.5–3 kHz. In contrast, the normalised dissipation (represented by the real part of the impedance) ranged from to . These results indicate that structures enclosing the vocal tract (e.g. oral and pharyngeal mucosa and muscle tissues), especially their mechanical properties, influence the transfer of the acoustical energy and the position and bandwidth of the formant frequencies. It implies that the timbre characteristics of vowel sounds are likely to be tuned by specific control of relaxation and strain of the surrounding structures of the vocal tract.

show abstract

Study of acoustic characteristics of vocal tract with nasal cavity during phonation of Japanese /a/

Cited by 11 publications

References 4 publications

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

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

Development of an Acoustic Simulation Method during Phonation of the Japanese Vowel /a/ by the Boundary Element Method

Formant frequencies and bandwidths of the vocal tract transfer function are affected by the mechanical impedance of the vocal tract wall

Contact Info

Product

Resources

About