Duration of ambulatory monitoring needed to accurately estimate voice use

Voice use is considered to play a major role in the development of many voice disorders, and clinicians focus on evaluating and modifying how patients use their voices throughout the day. Some voice monitoring devices have used neck-mounted accelerometers to unobtrusively and confidentially track voice use–related measures, such as phonation time, fundamental frequency, and sound intensity. Guidelines for the clinical use of such monitoring devices have yet to be established. This is a preliminary investigation into establishing initial benchmarks for obtaining robust estimates of long-term average voice use that may be used to begin examining basic relationships between vocal loading and voice use–related pathology. As expected, adequate monitoring durations depend on the inherent variability of the parameter of interest, with much of the error decreased after 26 hours of monitoring. Investigations are currently under way to take advantage of a smartphone-based voice monitoring system that is designed to enhance device wearability and enable the derivation of new clinically relevant measures.