Perceptual Evaluation of Vocal Fold Vibratory Asymmetry

Abstract

Objectives: Laryngeal vibratory asymmetry occurring with paresis may result in a perceptually normal or abnormal voice. The present study aims to determine the relationships between the degree of vibratory asymmetry, acoustic measures, and perception of sound stimuli.Study Design: Animal Model of Voice Production, Perceptual Analysis of Voice. Methods: In an in vivo canine model of phonation, symmetric and asymmetric laryngeal vibration were obtained via graded unilateral recurrent laryngeal nerve (RLN) stimulation simulating near paralysis to full activation. Phonation was performed at various contralateral RLN and bilateral superior laryngeal nerve stimulation levels. Naïve listeners rated the perceptual quality of 182 unique phonatory samples using a visual sort-and-rate task. Cepstral peak prominence (CPP) was calculated for each phonatory condition. The relationships among vibratory symmetry, CPP, and perceptual ratings were evaluated.Results: A significant relationship emerged between RLN stimulation and perceptual rating, such that sound samples from low RLN levels were preferred to those from high RLN levels. When symmetric vibration was achieved at mid-RLN stimulation, listeners preferred samples from symmetric vibration over those from asymmetric vibration. However, when symmetry was achieved at high RLN levels, a strained voice quality resulted that listeners dispreferred over asymmetric conditions at lower RLN levels. CPP did not have a linear relationship with perceptual ratings.Conclusions: Laryngeal vibratory asymmetry produces variable perceptual differences in phonatory sound quality. Though CPP has been correlated with dysphonia in previous research, its complex relationship with quality limits its usefulness as clinical marker of voice quality perception.

Effects of Thyroarytenoid Activation Induced Vibratory Asymmetry on Voice Acoustics and Perception

“…1). 16 This study design has been previously validated with adequate inter and intra‐rater reliability.…”

“…An in vivo canine model with graded nerve stimulation, which is a validated method for a direct manipulation of individual laryngeal muscle stimulation, 1 can offer insights on compensatory neuromuscular rescue of vibratory asymmetry. 15,16 However, no prior studies have examined the role of the individual ILMs responsible for VF asymmetry. Despite its importance in voice production, little is known about their contributions in producing VF asymmetries.…”

“…Finally, manipulating the degree of VF asymmetry was unavailable in many previous studies. An in vivo canine model with graded nerve stimulation, which is a validated method for a direct manipulation of individual laryngeal muscle stimulation, 1 can offer insights on compensatory neuromuscular rescue of vibratory asymmetry 15,16 . However, no prior studies have examined the role of the individual ILMs responsible for VF asymmetry.…”

Machine-learning applied to classify flow-induced sound parameters from simulated human voice

“…Vocal Fold Motion Symmetry In regular phonation, the left and right vocal fold oscillate symmetrically. However, in the case of laryngeal unilateral paresis or unbalanced muscle tension, the vocal folds oscillate asymmetrically [48,49]. Therefore, the proposed simulation model features two cases of vocal fold motion symmetry.…”