Vocal tract shape and acoustic adjustments of children during phonation into narrow flow-resistant tubes

Abstract

How the peak glottal area affects linear predictive coding-based formant estimates of vowels

Oral vibratory sensations during voice production at different laryngeal and semi-occluded vocal tract configurations

“…In other words, maximizing oral SPL with semi-occlusion at the lips does not facilitate any consistent vocal tract changes in the epilarynx in most people, and may lead to slight expansion in the epilarynx in speakers with high acuity to vibratory sensations. This is consistent with the observation in recent imaging studies that SOVTE often lead to widening of the epilarynx [e. This insensitivity of oral SPL to epilaryngeal tube manipulations in semi-occluded vocal tracts is due to the small effect of epilaryngeal manipulations on the first formant in semi-occluded vocal tracts, in which the first formant is determined mainly by the acoustic compliance of the air inside the vocal tract volume and the acoustic mass of the vocal tract wall, as shown in previous studies (Stevens, 1998;Patel et al, 2019). The contribution of vocal tract wall inertance to the first formant becomes important when the lip constriction provides a higher impedance to the oscillating airflow than the vocal tract wall, as shown in Patel et al (2019).…”

“…This is consistent with the observation in recent imaging studies that SOVTE often lead to widening of the epilarynx [e. This insensitivity of oral SPL to epilaryngeal tube manipulations in semi-occluded vocal tracts is due to the small effect of epilaryngeal manipulations on the first formant in semi-occluded vocal tracts, in which the first formant is determined mainly by the acoustic compliance of the air inside the vocal tract volume and the acoustic mass of the vocal tract wall, as shown in previous studies (Stevens, 1998;Patel et al, 2019). The contribution of vocal tract wall inertance to the first formant becomes important when the lip constriction provides a higher impedance to the oscillating airflow than the vocal tract wall, as shown in Patel et al (2019). Thus, this insensitivity of first formant and oral SPL to epilaryngeal manipulations is expected to vary depending on both the vocal tract wall properties (e.g., relaxed vs tensed cheeks) and degree of semi-occlusion at the lips (mouth opening area, or the diameter and length of a constricting tube if present), which is worth further investigation.…”

“…This reduced sensitivity is because for a vocal tract constricted in both ends, as in the case of the last two vocal tract configurations in Fig. 2, the first formant is related to vocal tract wall impedance and the acoustic compliance associated with the overall vocal tract volume (Stevens, 1998;Patel et al, 2019). Under such conditions, epilaryngeal manipulation is expected to have minimal effect on the first formant, as shown in Fig.…”

“…While there have been many studies investigating changes in laryngeal and vocal tract configurations during and after SOVTE (Vampola et al, 2011;Laukkanen et al, 2012;Guzman et al, 2013a,b;Guzman et al, 2017;Hampala et al, 2015;Patel et al, 2019;Lulich and Patel, 2021), the findings are not always consistent with theoretical predictions. These imaging studies generally reported a lower vertical laryngeal position after the exercises, indicating an elongated vocal tract.…”

Variation in the articulation of Russian stressed vowels and the mechanics of palatalization in consonants

“…Fully uncompressed DICOM ultrasound files were transferred from the ultrasound machine to a Windows 10 computer for analysis. The DICOM files were analyzed with a custom MATLAB toolbox called "WASL", 8 following Charles & Lulich (2018, 2019, Patel et al (2019), , and Cavar et al (2020).…”