Assessment of the Motor Speech Profile Tremor Analysis in Vocal Tremor Diagnosis

To assess the ability of the Motor Speech Profile (MSP) tremor analysis to distinguish vocal tremor from other laryngeal disorders.

We conducted a retrospective analysis of 169 adult voice recordings evaluated at a tertiary academic medical center. The cohort included adults with vocal tremor, muscle tension dysphonia, and neurologic voice disorders. All recordings were analyzed using the MSP tremor analysis protocol to extract acoustic tremor metrics.

Acoustic analysis indicated that the MSP tremor analysis protocol did not reliably distinguish vocal tremor from other laryngeal and neurological disorders. Tremor metrics, including coefficients of variation, magnitude, rate, and periodicity of frequency and amplitude, demonstrated wide variability and substantial overlap across diagnostic categories, most notably between vocal tremor and muscle tension dysphonia. Although select magnitude-based metrics showed statistically significant associations with vocal tremor presence, effect sizes were modest and overlap remained considerable.

Our findings suggest that within a clinically heterogeneous population, the MSP tremor analysis demonstrates metrics with substantial overlap across nonmutually exclusive diagnostic categories. This limits the software's ability to reliably identify vocal tremor when used in isolation. Given these limitations, acoustic tremor measures should be interpreted cautiously and considered as part of a multimodal clinical assessment rather than as stand-alone diagnostic tools.