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

Fleischer, Mario; Pinkert, Silke; Mattheus, Willy; Mainka, Alexander; Mürbe, Dirk

doi:10.1007/s10237-014-0632-2

Cited by 42 publications

(25 citation statements)

References 45 publications

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“…We suppose that the deviations of the formant frequencies of the realistic replicas in comparison to the subjects' formant frequencies are due to the rigid walls of the VT replicas. This effect of a frequency shift to lower frequencies at rigid walls compared with reflection at tissue was also reported by Fleischer et al [55] and Kitamura et al [14]. Another possible explanation for the appearing deviations are potential inaccuracies of the VT air volume due to the segmentation process.…”

Section: Analysis Of the Formant Frequenciessupporting

confidence: 74%

Acoustic and Aerodynamic Coupling during Phonation in MRI-Based Vocal Tract Replicas

et al. 2019

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Voiced speech is the result of a fluid-structure-acoustic interaction in larynx and vocal tract (VT). Previous studies show a strong influence of the VT on this interaction process, but are limited to individually obtained VT geometries. In order to overcome this restriction and to provide a more general VT replica, we computed a simplified, averaged VT geometry for the vowel /a/. The basis for that were MRI-derived cross-sections along the straightened VT centerline of six professional tenors. The resulting mean VT replica, as well as realistic and simplified VT replicas of each tenor were 3D-printed for experiments with silicone vocal folds that show flow-induced oscillations. Our results reveal that all replicas, including the mean VT, reproduce the characteristic formants with mean deviations of 12% when compared with the subjects' audio recordings. The overall formant structure neither is impaired by the averaging process, nor by the simplified geometry. Nonetheless, alterations in the broadband, non-harmonic portions of the sound spectrum indicate changed aerodynamic characteristics within the simplified VT. In conclusion, our mean VT replica shows similar formant properties as found in vivo. This indicates that the mean VT geometry is suitable for further investigations of the fluid-structure-acoustic interaction during phonation.

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Section: Analysis Of the Formant Frequenciessupporting

confidence: 74%

Acoustic and Aerodynamic Coupling during Phonation in MRI-Based Vocal Tract Replicas

et al. 2019

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“…Formant bandwidths are determined by several factors that conceivably could be affected by the gravitational orientation of the VT. These include radiation, friction, and heat conduction losses, and dissipation in the walls of the VT (Fant, 1972;Fleischer et al, 2014). We assumed that measurement of two formant bandwidths would be adequate to determine if bandwidths are affected by body position although it is possible that such effects are formant specific.…”

Section: Speech Acoustic Recordings and Measurementsmentioning

confidence: 99%

Effect of body position on vocal tract acoustics: Acoustic pharyngometry and vowel formants

Vorperian

Kurtzweil

Fourakis

et al. 2015

The Journal of the Acoustical Society of America

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The anatomic basis and articulatory features of speech production are often studied with imaging studies that are typically acquired in the supine body position. It is important to determine if changes in body orientation to the gravitational field alter vocal tract dimensions and speech acoustics. The purpose of this study was to assess the effect of body position (upright versus supine) on (1) oral and pharyngeal measurements derived from acoustic pharyngometry and (2) acoustic measurements of fundamental frequency (F0) and the first four formant frequencies (F1-F4) for the quadrilateral point vowels. Data were obtained for 27 male and female participants, aged 17 to 35 yrs. Acoustic pharyngometry showed a statistically significant effect of body position on volumetric measurements, with smaller values in the supine than upright position, but no changes in length measurements. Acoustic analyses of vowels showed significantly larger values in the supine than upright position for the variables of F0, F3, and the Euclidean distance from the centroid to each corner vowel in the F1-F2-F3 space. Changes in body position affected measurements of vocal tract volume but not length. Body position also affected the aforementioned acoustic variables, but the main vowel formants were preserved.

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“…To end this introductory section, we would like to remark that aside from static vowel sounds, for which an extensive literature is available (see, eg, literature [38][39][40][41][42][43][44][45][46][47][48][49] ), few papers can be found addressing the numerical simulation of other speech sounds. The reason for that is probably the complex physics beneath their generation and the associated high computational cost.…”

Section: Introductionmentioning

confidence: 99%

Computational aeroacoustics to identify sound sources in the generation of sibilant /s/

Pont

Guasch

Baiges

et al. 2018

Numer Methods Biomed Eng

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A sibilant fricative /s/ is generated when the turbulent jet in the narrow channel between the tongue blade and the hard palate is deflected downwards through the space between the upper and lower incisors and then impinges the space between the lower incisors and the lower lip. The flow eddies in that region become a source of direct aerodynamic sound, which is also diffracted by the speech articulators and radiated outwards. The numerical simulation of these phenomena is complex. The spectrum of an /s/ typically peaks between 4 and 10 kHz, which implies that very fine computational meshes are needed to capture the eddies producing such high frequencies. In this work, a large-scale computation of the aeroacoustics of /s/ has been performed for a realistic vocal tract geometry, resorting to two different acoustic analogies. A stabilized finite element method that acts as a large eddy simulation model has been adopted to solve the flow dynamics. Also, a numerical strategy has been implemented that allows the determination, in a single computational run, of the separate contribution of the sound diffracted by the upper incisors from the overall radiated sound. Results are presented for points located close to the lip opening showing the relative influence of the upper teeth depending on frequency.

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

Cited by 42 publications

References 45 publications

Acoustic and Aerodynamic Coupling during Phonation in MRI-Based Vocal Tract Replicas

Acoustic and Aerodynamic Coupling during Phonation in MRI-Based Vocal Tract Replicas

Effect of body position on vocal tract acoustics: Acoustic pharyngometry and vowel formants

Computational aeroacoustics to identify sound sources in the generation of sibilant /s/

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