Test-retest reliability and discriminatory power of multidimensional voice analysis program.

OBJECTIVES: The objectives of this study were to evaluate and compare the test-retest reliability of acoustic parameters (jitter [%], shimmer [%], noise-to-harmonic ratio [NHR], and voice turbulence index [VTI]) by using multidimensional voice program, and to detect the discriminatory power of the acoustic measures with respect to dysphonic voices and normal voices. DESIGN, SETTING, PARTICIPANTS, AND METHODS: Fifty-four (25 male and 29 female) participants with voice disorders and fifty-one (27 male and 24 female) participants with normal voices were enrolled in this study. They were assessed by anamnesis, visual examination, auditory perceptual assessment (GRBAS), and acoustic measurements. The intraclass correlation coefficient was used to determine the test-retest reliability. The effect size (d value) and p value obtained from the t-test were used to determine the discriminatory power. RESULTS: In the normal group, good reliability was observed for jitter, shimmer, and NHR, and moderate reliability was observed for VTI. With regard to the dysphonic group, jitter, shimmer, and VTI were moderately reliable, and the NHR had good reliability. Meanwhile, the discriminatory powers of jitter and shimmer were evaluated as 'medium', and those of NHR and VTI as 'small'. CONCLUSION: The reliability and discriminatory powers of our acoustic measures were high compared with most other studies. Their level of reliability and discriminatory power can be maximised by using stringent rules. However, attaining an excellent level of reliability and discriminatory seems infeasible power owing to the variable characteristic of voice. Therefore, acoustic measures should be adopted as a complementary tool.

Effects of Smoking on the Auditory System: Is There a Gender Difference?

The main aim of our study is to evaluate whether the effect of smoking on the auditory system shows gender differences. Another aim is to evaluate whether smoking has any influence on the absorbance of sound. There were 236 volunteers including 90 nonsmokers (42 females and 48 males) and 146 smokers (72 females and 74 males) in the study. Smokers were grouped according to pack-years of smoking as 5 to 10 pack-years, 11 to 20 pack-years, and more than 20 pack-years. Pure tone audiometry and wideband tympanometry were performed in all individuals. Both female and male smokers who consume more than 20 pack-years had significantly higher hearing thresholds at 4 and 6 kHz and significantly lower sound energy absorbance rates at 4, 6, and 8 kHz. Moreover, female smokers with a consumption of 11 to 20 pack-years had significantly higher hearing thresholds at 6 kHz and significantly lower sound energy absorbance rates at 6 and 8 kHz. Smoking causes hearing loss at high frequencies in both females and males, especially in a dose-dependent manner affecting individuals with a consumption of more than 20 pack-years. The sound energy absorbance is significantly reduced at 4, 6, and 8 kHz. In addition, these effects may occur in women with even less exposure.