The impact of glottal area discontinuities on block-type vocal fold models with asymmetric tissue properties

Abstract

Block-type lumped-element models of the vocal folds are widely used for speech investigations due in part to the rich dynamics exhibited over a range of input parameters, particularly for asymmetric tissue properties. While self-consistent in derivation and application, block-type models of the vocal fold masses are inherently susceptible to non-physical aerodynamic loading conditions when vocal fold motion is highly asymmetric. A standard block-type model is compared against two modified models that disallow the non-physiological loading condition. These minor modifications toward a more physiologically relevant aerodynamic model alter the specific vibration regimes and prevalence of chaos, though bifurcations still exist.

Asymmetric triangular body-cover model of the VFs with bilateral intrinsic muscle activation

“…However, studying VF oscillation with diverse properties presents several challenges, including the presence of harmonics, as illustrated in Figure 5, a topic extensively explored by other researchers (Sommer et al ., 2013; Steinecke and Herzel, 1995; Zhang and Jiang, 2004). Another critical consideration is the impact of the chosen reference point, whether it pertains to muscular activation or the specific values assigned to masses and springs.…”

“…Prior studies employing modeling techniques have investigated asymmetries in VF to comprehend their underlying etiology and explore potential clinical interventions (Lucero et al ., 2020; Mehta et al ., 2011; Zhang and Luu, 2012). However, within the context of lumped-element models, asymmetry has primarily focused on geometrical and mechanical distinctions between the folds (Dresel et al ., 2006; Erath et al ., 2011; Mehta et al ., 2011; Sommer et al ., 2013; Steinecke and Herzel, 1995; Xue et al ., 2010).…”