Ambulatory monitoring of a vocal efficiency index to improve the clinical management of voice disorders

Project Summary/Abstract In the United States, voice disorders affect approximately 30% of the adult population at some point in their lives, with about 25 million individuals suffering at any given point in time. The impact of living with a voice disorder is far-reaching, and the societal burden reaches up to $13.5 billion dollars each year due to work-related disability, lost productivity, and direct healthcare costs. Individuals with voice disorders often suffer from heightened sensations of vocal effort and fatigue while speaking that are typically attributed to inefficient vocal function and behavior. Increasing vocal efficiency and decreasing vocal effort and associated vocal fatigue are often goals of clinical treatment paradigms. Thus, vocal efficiency is a highly desirable objective measure for the clinical management of voice disorders, particularly if it can be obtained via ambulatory monitoring to track vocal health and vocal behavior in a patient’s natural environment. The proposed project seeks to develop an index of ambulatory vocal efficiency that integrates estimates of subglottal pressure and vocal sound pressure level to monitor the vocal effort of patients being treated for phonotraumatic vocal cord lesions, non-phonotraumatic vocal hyperfunction, and unilateral vocal fold paralysis. Individuals with healthy vocal status will also be monitored as control subjects matched for sex, age, and occupational/vocal demands. An innovative wearable sensor technology using flexible circuits obtains synchronized data from a wireless neck-surface accelerometer and microphone to track the index of ambulatory vocal efficiency in real-world settings. Integrating the technology into a smartphone platform enables periodic prompting to prompt subjects to rate their level of vocal effort on a visual analog scale. The proposed work pursues critical goals of (a) investigating the clinical validity of the ambulatory vocal efficiency index in patients with voice disorders and vocally healthy matched controls and (b) assessing the ambulatory vocal efficiency index as an objective correlate of self-ratings of vocal effort. The impact of this work is significant because, for the first time, voice clinicians will be able to monitor vocal efficiency in naturalistic, real-world settings to improve the prevention, diagnosis, and treatment of voice disorders.