Direct Comparison of Three Commercially Available Devices for Voice Ambulatory Monitoring and Biofeedback

Purpose: To provide a direct comparison of three commercially available devices for voice ambulatory monitoring and biofeedback to assist voice clinicians and researchers in choosing the device that best meets their needs. Methods: The Ambulatory Phonation Monitor (APM), VocaLog, and VoxLog were descriptively compared regarding cost, availability, physical characteristics, and operational features; and quantitatively compared regarding measures of loudness (dB sound pressure level [SPL]), pitch (fundamental frequency – F0), and phonation time. The quantitative comparison used simultaneous registrations acquired during a 90-minute lecture which also included a Smartphone-based system designed to capture the raw voice signal as a reference. Results: Differences regarding cost, physical characteristics, and operational features could influence device choice. All three devices register SPL and phonation time, and also biofeedback based on SPL. Furthermore, the APM and VoxLog provide monitoring and biofeedback for F0 with the associated capability of providing additional measures related to vocal dose. All devices produced comparable results for common measures, except for the overestimation of phonation time by the VocaLog. Conclusions: The cost, operational features, and performance characteristics of the three commercially available devices for voice ambulatory monitoring and biofeedback differ in ways that can significantly impact decisions about which one is best suited for a particular application.