Validation of the Dysphonia Severity Index in the Dr. Speech Program

The Dysphonia Severity Index (DSI) is an objective multiparameter index of voice quality that measures and describes overall voice quality. Some studies have suggested that the reliability of devices for DSI measurement should be examined. We explored the feasibility of DSI measurements using the Dr. Speech (DRS) device, verified its effectiveness for clinical voice measurements and intradevice reliability, and examined the correlation between the DSI and self-evaluations of voice problems.

Seventy adult participants (including individuals with voice problems and healthy adults) underwent objective and subjective voice assessments. These data were then used to establish a DSI_DRS model and test the intradevice (DRS device and Praat software) reliability. The clinical validation of the DSI_DRS was conducted by measuring the DSI of six other participants and comparing the observed and predicted perceived voice quality as expressed by the G score (of the GRBAS scale). Moreover, the relationship between the DSI measurements and participants' self-evaluations of voice problems was investigated by analyzing the correlation between the DSI and the Voice Handicap Index (VHI).

The DSI_DRS discriminated 80% of participants' voice quality ratings. There were strong correlations between the DSI and variables measured by the DRS device and Praat software. Furthermore, there was no significant correlation between the DSI_DRS and VHI.

The DRS device can perform DSI measurements. Objective voice measurements and perceptual voice ratings reflected different aspects of vocal function and its effects. These factors should be considered in clinical practice settings.