Acoustic Measures Most Predictive of Botulinum Toxin Treatment Outcomes in Adductor-type Laryngeal Dystonia

Jenny L. Pierce, PhD | University of Utah

Dr. Jenny L. Pierce is a recipient of the 2023 Dysphonia International Research Travel Award in partnership with The Voice Foundation. Dr. Pierce participated in the 2023 Voice Foundation Conference and presented research entitled, “Acoustic Measures Most Predictive of Botulinum Toxin Treatment Outcomes in Adductor-type Laryngeal Dystonia.”

When asked what it meant to attend The Fall Voice Conference, Dr. Pierce stated “Attending this meeting was crucial to disseminate our important research. The long-term goal of our work is to improve treatment options for people with laryngeal dystonia, and attending this meeting helped us make a short-term step toward that goal.”

Below is an abstract of Dr. Pierce’s podium presentation.


Additional Authors: Kaitlyn Dwenger, Skyler Jennings, Anuja Sharma, Marshall Smith, Julie Barkmeier-Kraemer

Introduction: Injection of botulinum toxin (BoNT) into the laryngeal muscles is the current standard treatment for laryngeal dystonia (LD); in addition, novel treatment approaches are being developed. Unfortunately, there is no agreed upon voice acoustic measure that reliably and validly quantifies LD treatment outcomes, although several have been proposed. This study compared standard and newer acoustic measures pre- and post-BoNT treatment to determine which should be used in future treatment studies.    

Methods: A within subject treatment outcome research design was conducted. Eleven participants with adductor-type LD completed voice acoustic recordings of voice-loaded sentences pre-BoNT injections and post- when their voice was at maximum benefit. Smoothed cepstral peak prominence (CPPS) from three different software programs was compared to identify the version optimally associated with voice improvement. Programs used to estimate CPPS were Praat v. 6.3.09, Analysis of Dysphonia in Speech and Voice (ADSV), and a MatLab script based on Hillenbrand & Houde, 1996. In addition, cepstral spectral index of dysphonia (CSID), percent (%) creak, and a measure of vocal strain based on perceptual sharpness were measured. Analyses comparing pre to post BoNT treatment measurement included Cohen’s D effect sizes, Pearson correlation with listener ratings and the Voice Handicap Index-10 (VHI-10), and a mixed effects model.    

Results: Significant differences were found on most acoustic measures from pre- to post-BoNT: CPPS-MatLab (<0.001), CPPS-Praat (<0.001), CPPS-ADSV (<0.001), CSID (<0.001), %creak (<0.001), and strain (0.72). Large effect sizes were found in the CPPS measures: CPPS-ADSV (1.00), CPPS-Praat (0.95), CPPS-MatLab (0.95), CSID (0.66), %creak (0.44), and strain (0.06). Five of the six measures reflected general improvement in voice quality (n): CPPS-Matlab (12), CPPS-ADSV (11), CPPS-Praat (11), CSID (11), %creak (10), and strain (4). Strong correlation coefficients with listener ratings were found in two CPPS measures: CPPS-Praat (0.68), CPPS-ADSV (0.64), CSID (0.51), %creak (0.42), CPPS-Matlab (0.41), and strain (0.03). There were no strong correlation coefficients with VHI-10: CPPS-Praat (0.49), CPPS-ADSV (0.32), CPPS-Matlab (0.23), %creak (0.20), strain (0.12), and CSID (0.04).    

Conclusions: CPPS consistently outperformed other acoustic measures. In particular, CPPS-Praat and CPPS-ADSV are recommended for application in future work evaluating treatment outcomes in AdLD.

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The Fall Voice Conference is designed to encourage and educate professionals on a multi-disciplinary approach to the management of vocal disorders. The focus of this conference is the clinical care of patients with voice-related difficulties and how clinical and basic science research guide clinical care. For more information:

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