Acoustic and kinematic estimates of laryngeal stiffness

• Published in: The Journal of the Acoustical Society of America 2016-04, Vol.139 (4), p.2193-2193
• Main Authors: McKenna, Victoria S., Heller Murray, Elizabeth S., Lien, Yu-An S., Stepp, Cara E.
• Format: Article
• Language: English
• ISSN: 0001-4966; 1520-8524
• DOI: 10.1121/1.4950529

Vocal fold movements differ between individuals with typical voices and those with voice disorders associated with increased laryngeal stiffness. Modeling suggests that changes in vocal fold kinematics correspond to changes in laryngeal muscle stiffness. In this study, 12 healthy adults produced repetitions of /ifi/ while varying their self-perceived vocal effort during simultaneous acoustic and nasal-endoscopic recordings, in order to compare a kinematic estimate of laryngeal stiffness to an acoustic measure. The acoustic measure, relative fundamental frequency (RFF), was determined from the last ten voicing cycles before the voiceless obstruent (offset) and the first ten voicing cycles of the following vowel (onset). A kinematic stiffness ratio was calculated by normalizing the maximum angular velocity by the maximum value of the glottic angle during vocal fold adductory gestures. A linear mixed-effect model found that RFF accounted for 52% of the variance in the kinematic data. Examined within-subject, 83% of participants exhibited at least a moderate negative linear relationship (r = −0.5 to −0.91) between the offset cycle 10 RFF and the kinematic stiffness ratio. Overall, the relationship between the acoustic and kinematic measures was strong and both measures showed consistent changes during self-modulated changes in vocal effort.