ABSTRACT
The harmful effects of smoking cigarette on body organs are well documented. There are more than 40 acoustic voice parameters and the effects of smoking cigarette on them are still studied. The aim of this study was to examine and compare some acoustic voice parameters between smoker and non smoker men. In this cross-sectional study, some acoustic voice parameters including; fundamental frequency, jitter, shimmer, irregularity, contact quotient and elements of speech pattern were compared between 2 groups of men consisting of 20 smokers and 20 non-smokers. Each parameter was calculated using speech studio software and an electrolaryngograph. The men's voices differed on several parameters. The mean fundamental frequency in smokers was significantly lower [P<0.001] than this one in non-smokers. The mean jitter, shimmer and irregularity of men who smoke were significantly higher [P<0.001] than those mean in the men who did not. The mean silence among smokers was significantly higher [P<0.001] than that mean among nonsmokers. In contrast, the mean of voicing in the men who smoke was significantly lower [P<0.001]. No significant difference was observed between the two groups with respect to contact quotient, nasality, and friction. Fundamental frequency is the most vulnerable acoustic parameter of voice in smokers. The higher means for jitter shimmer and irregularity of voice in men who smoke is most likely related to epithelial changes in the vocal folds, inflammation caused by cigarette smoking, and the neurologic effects of nicotine and other chemical materials of cigarettes. It seems that the increased time of silence during connected speech of smokers is related to the defective quality of the closed phase of vocal cords movement
Subject(s)
Humans , Male , Voice , Acoustics , Speech , Cross-Sectional StudiesABSTRACT
By means of normal hearing system and appropriate auditory feedback, we can control acoustic parameters of voice such as phonation, quality of voice, pitch and intensity. The aim of this cross-sectional study was investigation and comparison of some acoustic parameters of voice including: mean of intensity range, frequency range, shimmer, and harmonic to noise ratio between 2 groups of children [17 hearing impaired and 17 normal children]. These groups were matched with respect to age and sex. The mean of each parameters were calculated using collection of speech studio software and electrolaryngograph apparatus and were compared between two groups of children. The mean of intensity range between two groups was not statistically different [P=0.462]. The mean of frequency range between two groups was not statistically different either [P=0.277]. The mean of Shimmer in children with hearing loss was higher than normal children [P=0.010]. The mean of Harmonic to noise ratio [HNR] in children with hearing loss was lower than normal children [P=0.001]. It can be concluded that most susceptible acoustic parameters of voice for improving by hearing aids and speech therapy services are frequency and intensity range. The higher mean of shimmer and lower mean of harmonic to noise ratio [HNR] in hearing impaired children in comparison with normal group is caused by excessive pressure that these children are bearing on the larynx and related structures