Comparison of Acoustic Parameters in Normal Girls and Girls with Down Syndrome

Down syndrome is the most common cause of mental impairment.. Most people with Down syndrome experience difficulties in verbal communication and abnormal voice quality in these children reduces their opportunities for good communication. The aim of this study was to estimate the acoustic parameters in children with Down syndrome and normal children in order to achieve a quick indicator for assessment and treatment. Subjects and This is a cross-sectional and descriptive- analytical study. In this study the voice samples of 20 children with Down syndrome and normal children between 4-8 years (average =4. 6، SD= 1. 46 years). Normal children matched for age and sex. Voice samples were analyzed by using Praat software. To investigate the difference between data، independent samples tests were used. The mean of fundamental frequency (F0) in children with Down syndrome were significantly lower than the control group (P = 0. 009). Comparison of Jitter in the two groups showed a significant increase in this parameter in children with Down syndrome than in the control group (P= 0. 004). Comparing the results of shimmer parameter was the same as jitter (P ‹ 0/000) and the Harmonic-to-Noise Ratio (HNR) parameter in children with Down syndrome than in the control group showed a significant decrease. The results show that during the assessment and treatment acoustic evaluation can improve the accuracy and speed. And also use of acoustic parameters can lead to accurately plan treatment and direct focus on the defects.