The Effect of Smoking on the Dysphonia Severity Index in Females

Objective: This study investigated the capability of the Dysphonia Severity Index (DSI) and its component measures to reveal differences in vocal capability between groups of young adult female smokers and nonsmokers. Patients and Methods: The subjects were 30 female nonsmokers and 30 female smokers between the ages of 18 and 24 years. Data on the DSI components (maximum phonation time, MPT; highest phonational frequency, F-0 (high); lowest intensity, I-low, and jitter) were collected, followed by calculation of the DSI. Results: Significant differences between groups were observed on the DSI, with reduced DSI scores in smokers primarily due to reductions in F-0 (high) and increases in I-low. A strong partial correlation between MPT and the DSI in smokers may be indicative of reductions in respiratory support and/or phonatory control. Conclusions: Significant group differences in the DSI and component measures may be indicative of early changes in vocal function secondary to smoking. Reductions in frequency and dynamic range are consistent with the possibility of increased vocal fold mass in smokers. The results indicate that significant differences in the DSI between groups may be observed in subjects with perceptually normal vocal quality and with normal levels of vocal perturbation. Copyright (C) 2010 S. Karger AG, Basel