Evaluating sensory tricks in laryngeal dystonia (Dwenger et al., 2025)

Purpose: This pilot study systematically compared voice symptomatology across varied sensory trick conditions in those with laryngeal dystonia (LD), those with essential vocal tremor (EVT), and vocally normal controls (NCs). Sensory tricks are considered signature characteristics of dystonia and were hypothesized to reduce voice symptoms in those with LD compared to EVT and NC groups.

Method: Five participants from each group (LD, EVT, and NC) completed speech recordings under control and sensory trick conditions (delayed auditory feedback [DAF], vibrotactile stimulation [VTS], and nasoendoscopic recordings with and without topical anesthesia). Comparisons between groups and conditions were made using (a) a paired-comparison paradigm (control vs. sensory condition) listener ratings of voice quality, (b) participant-perceived vocal effort ratings, and (c) average smoothed cepstral peak prominence (CPPS).

Results: Participants with EVT displayed significantly worse listener ratings under most sensory trick conditions, whereas participants with LD were rated significantly worse for DAF and VTS conditions only. However, participant vocal effort ratings were similar across all sensory trick conditions. Average CPPS values generally supported listener ratings across conditions and speakers except during DAF, wherein CPPS values increased (i.e., measurably improved voice quality), whereas listener ratings indicated worsened voice quality for both voice disorder groups.

Conclusions: Outcomes of this study did not support the hypothesized influences of sensory trick conditions on LD voice symptoms, with both LD and EVT groups experiencing worsened symptoms under VTS and DAF conditions. These adverse effects on voice symptoms warrant further research to further evaluate neural pathways and associated sensorimotor response patterns that distinguish individuals with LD and EVT.

Supplemental Material S1. Descriptive statistics for the normal control group stratified by outcome measurement and condition.

Supplemental Material S2. Descriptive statistics for the laryngeal dystonia group stratified by outcome measurement and condition.

Supplemental Material S3. Descriptive statistics for the essential vocal tremor group stratified by outcome measurement and condition

Dwenger, K., Roy, N., Jennings, S. G., Smith, M. E., Mathy, P., Simonyan, K., & Barkmeier-Kraemer, J. M. (2025). Comparing the effects of sensory tricks on voice symptoms in patients with laryngeal dystonia and essential vocal tremor. Journal of Speech, Language, and Hearing Research. Advance online publication. https://doi.org/10.1044/2024_JSLHR-24-00476