Project Summary Laryngeal dystonia (LD) is a neurological voice disorder characterized by involuntary spasms of the laryngeal muscles during phonation, which significantly impacts psychosocial well-being and quality of life. The most common subtype of LD is adductor laryngeal dystonia (AdLD), which involves spasms of the laryngeal muscles that adduct the vocal folds, resulting in LD discontinuities. LD discontinuities are disruptions to the speech acoustic signal caused by the spasms and include phonatory breaks (voice breaks) and frequency shifts (pitch breaks) that are most severe during production of voiced sounds. A significant issue in treating AdLD is frequent misdiagnosis. AdLD is often mistaken for muscle tension dysphonia (MTD), a functional voice disorder with increased global laryngeal tension, but without laryngeal spasms. Clinical outcome measures for AdLD are non- specific to the primary signs of AdLD and/or clinically unfeasible . Recently, a new automated acoustic measure, based on spectral aggregate of the high-passed fundamental frequency contour (SAHfo) was designed to be sensitive to LD discontinuities specific to AdLD. However, before the measure can be implemented clinically, it is essential to assess whether SAHfo is related to and sensitive to changes in the core signs of AdLD: adductory laryngeal spasms and the resulting atypical phonatory events. The goal of this proposal is to investigate SAHfo as a clinically feasible outcome measure specific to AdLD. We will record high-speed videoendoscopy and speech acoustics of 30 adults with AdLD while they are in their most symptomatic state. In Aim 1, we will determine whether SAHfo reflects the primary signs of AdLD, comparing SAHfo (calculated automatically) to the number of LD discontinuities (calculated manually from the acoustic signal) and to the number of laryngeal spasms (computed during high-speed videoendoscopy). Results of this aim will provide essential evidence of concurrent validity of SAHfo as an outcome measure in AdLD. In Aim 2, we will record speech acoustics from 30 individuals with MTD to evaluate the discriminant validity of SAHfo, comparing its values in speakers with AdLD and speakers with MTD. A clinically feasible, objective measure of the primary signs of AdLD would be transformative for patients with AdLD, leading to earlier diagnoses and a path to successful evaluation of new treatments. Through this work, the applicant will build on her previous research experience with perceptual and aerodynamic measures by training in advanced acoustics and high-speed videoendoscopic methods. The training will take place at Boston University, with support from her sponsors: Dr. Stepp and Dr. Guenther. The training plan will include formal coursework in MATLAB and neural control of speech. This research will provide this promising investigator with the experience and expertise in psychometric analysis of objective measures as she embarks on a successful career as an...