Inter-device reliability of DSI measurement.

The Dysphonia Severity Index (DSI) is a measure that quantifies the overall vocal quality. The aim of the study is to evaluate the reliability of DSI measurements. The DSIs of 30 subjects were therefore measured using LingWAVES (WEVOSYS) and DiVAS (XION). To evaluate the inter-device reliability of DSI measurement, the devices' results were compared for each subject. The DSI values of both devices showed great differences. The calculated DSI differences of 95% of the subjects were within the limits of +2.39 and -2.82, which makes a clinical interpretation of severity of voice disorder using different devices questionable. The technical and procedural aspects of measurement divergences are discussed, and the need to define hardware and software standards is shown.