Vocal fold contact pressure in a three-dimensional body-cover phonation model

Abstract

The goal of this study is to identify vocal fold geometric and mechanical conditions that are likely to produce large contact pressure and thus high risk of vocal fold injury. Using a three-dimensional computational model of phonation, parametric simulations are performed with co-variations in vocal fold geometry and stiffness, with and without a vocal tract. For each simulation, the peak contact pressure is calculated. The results show that the subglottal pressure and the transverse stiffness of the vocal folds in the coronal plane have the largest and most consistent effect on the peak contact pressure, indicating the importance of maintaining a balance between the subglottal pressure and transverse stiffness to avoiding vocal fold injury. The presence of a vocal tract generally increases the peak contact pressure, particularly for an open-mouth vocal tract configuration. While a low degree of vocal fold approximation significantly reduces vocal fold contact pressure, for conditions of moderate and tight vocal fold approximation changes in vocal fold approximation may increase or decrease the peak contact pressure. The effects of the medial surface thickness and vocal fold stiffness along the anterior−posterior direction are similarly inconsistent and vary depending on other control parameters and the vocal tract configuration.

Interaction between epilaryngeal and laryngeal adjustments in regulating vocal fold contact pressure

“…This reduction is largely due to the improved voice production efficiency, which lowers the subglottal pressure required to produce an 80 dB SPL (lower panel in Figure 4 ). Because the subglottal pressure has the largest influence on the peak vocal fold contact pressure ( Zhang, 2019 ), this reduced subglottal pressure requirement leads to an overall reduced peak contact pressure, despite the inconsistent effect of epilaryngeal narrowing on the peak contact pressure as shown in Fig. 3 .…”

“…The same three-dimensional body-cover vocal fold model as in the study by Zhang (2020) is used in this study. The reader is referred to previous studies for details of the model ( Zhang, 2017 , 2019 , 2020 ). The vocal fold model is parameterized by various geometric and mechanical properties of the vocal folds ( Zhang, 2020 ).…”

“…The material control parameters for each vocal fold layer include the transverse Young's modulus E t , the AP Young's modulus E ap , the AP shear modulus G ap , and density. The effect of these mechanical properties on vocal fold contact pressure has been investigated in detail in the two studies by Zhang (2019 , 2020) . In this study, the body and cover layers have identical mechanical properties, with E t , G ap , and E ap set to 4 kPa, 10 kPa, and 40 kPa, respectively.…”

“…The glottal flow is modeled as a one-dimensional quasi-steady glottal flow model taking into consideration viscous loss, as described in detail in Zhang (2017) . Vocal fold contact occurs when portions of the vocal fold cross the glottal midline, in which case a penalty pressure along the medial-lateral direction into the vocal fold is applied to the contact surface of the vocal fold ( Zhang, 2019 ). A large enough penalty pressure will ensure small penetration depth of the vocal folds crossing the glottal midline, and the corresponding penalty pressure will approximate the true contact pressure ( Zhang, 2019 ).…”

Toward Development of a Vocal Fold Contact Pressure Probe: Bench-Top Validation of a Dual-Sensor Probe Using Excised Human Larynx Models

“…Accurate positioning of the intraglottal pressure sensor is expected to provide new insight into how collision pressure contributes to vocal fold trauma (e.g., how collision pressure varies with sound pressure level) and lead to the development of new measures that could improve prevention, diagnosis and treatment of phonotraumatic disorders. These data could also be used to help improve physical and computational models of voice production [13][14][15][16][17]. Figure 1 displays a photograph of the dual-sensor ISP probe and its dimensions.…”