Influence of gender and age on the Dysphonia Severity Index: A normative study in a Shanghainese population.

Dysphonia Severity Index (DSI) is an objective multi-parametric measurement of voice quality, which has been widely used in different countries. Studies indicate that DSI may be influenced by vocal pathology, age and geographical factors, whereas gender does not significantly affect DSI. The purpose of this study was to investigate the effects of gender and age on the DSI and related parameters in a Shanghainese population. The present study measured the DSI and the parameters maximum phonation time (MPT), highest fundamental frequency (HF0), lowest intensity (LI) and Jitter in 187 Shanghainese subjects, including 106 young adults aged 18-23 years (52 males and 54 females) and 81 children aged 7-9 years (44 boys and 37 girls). Two-way analysis of variance indicated that HF0 was significantly higher in female subjects than in male subjects, in both young adults and children. Gender was not significantly associated with MPT, LI, jitter or DSI. With regard to age, MPT and DSI were significantly higher in young adults than in children, and HF0 and LI were significantly lower. No significant associations between age and jitter were detected. In terms of clinic significance, the results of this study may contribute to the establishment of a normal reference range for Shanghainese DSI values, and the influence of gender and age on DSI and its separate components.