THE COMPARISON OF ACOUSTIC VOICE FEATURES IN SMOKERS AND NON-SMOKERS

Purpose: Smoking is one of the most important factors in laryngeal lesions and voice disorders. Larynx and voice make speech audible. Speech communication has undeniable and important role in human life. Investigation of the smoking effect on the smoker’s voice is necessary for prevention, treatment and rehabilitation plan. Methods: This cross- sectional study was performed on 45 smokers (34 male and 11 female, mean age: 38.4 ± 9.7 years) attending to stop smoking center of Beheshti University of Medical Sciences and 32 non-smokers (19 male and 13 female, age range: 28.43 ± 7.8 years)). The vowel /a/ was sustained for 5 seconds and the acoustic characteristics i.e. fundamental frequency and its variation, jitter, Shimmer, changes in amplitude and Noise to harmonic ratio was analyzed with MDVP software. Results: The results show that F0 and Fmin decreased in smokers and there is a significant difference with non-smokers (p<0.05). The NHR, vAm, Atri, vF0 in smokers are significantly higher than non-smokers (p<0.05). In addition, the relation between the number of cigarettes smoked per day showed that it has a significant correlation with parameters F0 (P=0.010; r=-0.374) and Fmin (p=0.004; r=-0.423) however, no significant correlation with acoustic voice features. Conclusion: Acoustic voice characteristics in individual who smokes longer were significantly reflects larynx and voice dysfunction. Smoking 15 cigarettes per day and more than 10 years can affect the larynx significantly and also disturbed voice.