Voice Change And Aerodynamic Analysis Of Adult Male Smokers

Cigarette smoking is a major disposing factor for an assortment of potentially fatal respiratory ailments. Chronic use of cigarettes often leads to laryngeal problems, such as chronic inflammation, laryngeal reflux, and all kinds of voice disorders. Previous research reported a lower fundamental frequency among smokers' voice. Aerodynamic studies reveal shorter maximum phonation times. However, no systematic voice analysis for smokers has yet been carried out. Nonlinear dynamic analysis is capable of analyzing voice samples that are not suitable for perturbation analysis and has been applied to both pathological and nonpathological voice samples. Nonlinear dynamic analysis has not been previously applied to voices of smokers. In this study, we try to quantify the effects of smoking on voice with systematic perturbation analysis, nonlinear dynamic analysis and aerodynamic analysis. Next, we try to establish a noninvasive system to estimate smokers'voice and laryngeal health, as to educate on no chief complaint smokers and to propaganda nonsmoking movement.Part one:Perturbation and nonlinear dynamic analysis of adult male smokers Objective:Smoking results in a voice change and the perception by smokers of an abnormal voice may encourage quitting behavior. Moreover, a disordered voice is often the first sign of vocal pathology. Efforts to evaluate voice have focused on classical acoustic analysis; however, nonlinear dynamic analysis has been shown to be a reliable objective method for the evaluation of voice. We compare the discriminatory ability of these two methods applied to normal and smokers'voices. Study Design:Prospective study. Methods:The study included 73 subjects,36 nonsmokers and 37 smokers. A segment of sustain vowel production was obtained from each subject. Acoustic and correlation dimension (D2) analysis was applied to the data. Results were compared with a Mann Whitney rank sum test, regression and ROC analysis. Results:D2 values for smokers were significantly higher than for nonsmokers (p<0.001). Jitter and shimmer analysis showed higher values for these parameters among smokers. Logistic regression indicated a higher predictive power with D2 and ROC analysis found no significant difference between the analysis methods. Discussion:This study indicated that correlation dimension is highly sensitive to changes associated with smoking and has the potential to be implemented clinically as an indicator of abnormal voice. Further research could focus on using nonlinear dynamic analysis to create a normative database, producing standards for monitoring voice changes caused by cigarette smoking.Part two:Aerodynamic analysis of adult male smokers Objective:Larynx is an energy transducer that transfers subglottal aerodynamic energy into acoustic energy. Aerodynamic analysis includes a serie of parameters that reveal the laryngeal function. As the minimum airflow required to initiate phonation, PTF is sensitive to subtle changes in laryngeal tissue properties, glottal configuration, and vocal tract loading. We compare the discriminatory ability of the aerodynamic parameters applied to normal and smokers'voices to find out the changes of glottal structure, including PTF and MFR. Study Design:Prospective study. Methods:The study included 73 subjects,36 nonsmokers and 37 smokers. Each subject was measured aerodynamic analysis. Results were compared with a Mann Whitney rank sum test. Results:Mean SGP values for smokers were higher than for nonsmokers, mean PTF and MFR values for smokers were lower than for nonsmokers, but without significant difference (p>0.05). Discussion:Aerodynamic results are influenced by many factors. As a new parameter, PTF requires further technique improvement in order to be applied in the clinic. Further research could focus on combining aerodynamic measurements, acoustic analysis and clinical rigid scope examinations in order to quantitatively diagnose the effects of smoking on larynx.