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Background and aim: Noise pollution is one of the main cause of occupational hearing loss. According to WHO reports in many countries workers have been exposed to 85 - 90 dB noise level. The purpose of this study is to manufacture a sound absorber based on combined recycled polyethylene trephetalat (PET) and polystyrene (PS) with an economical method in order to control of noise pollution
Materials and methods: Sound absorber were made of PET and PS with equal weight percent, polyester fiber, and polyvinyl acetate resine, with five to ten centimeters thick. Sound mean absorption coefficient percents were determined by acoustic impedance tube and compared with those of rock wool.
Results: Mean absorption coefficient percent of  samples with one to five millimeter pore size and ten centimeters thickness was significantly better than those with six to twenty millimeters pore size in 50 to 630, 1250, and 1600 Hz, (p<0.05). In general, samples mean absorption coehicient was significally different from those rock wool (p=0.005).
Conclusion: Recycle polymere absorbers may play an important role in national economics as they are prophylactic to some occupational disease and also are economical.

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Background and Aim: Diabetes mellitus is a progressive metabolic disease. Studies about the relationship between diabetes mellitus and auditory impairment have shown variable results in supporting the fact that diabetes may have a complex repercussion on the auditory pathways. We aimed to evaluate hearing in patients with type II diabetes mellitus with behavioral and electrophysiological auditory tests.

Methods: In a cross-sectional study, we assessed 30 patients with type II diabetes mellitus with the mean age of 43.7 (SD: 1.3) years, ranging 40-45 years, and 30 matched healthy subjects with the mean age of 41.5 (SD: 1.5) years. Subjects were evaluated using auditory brainstem response (ABR) and pure tone audiometry. The results were compared between two groups.

Results: Pure tone audiometry was normal. There was a significant increased latency for waves I, III, and V, and also, interpeak latencies of I-III, III-V, and I-V waves (p<0.05).

Conclusion: ABR latency prolongation indicates abnormal nerve conduction velocity in patients with type II diabetes mellitus. ABR can be an important clinical tool for evaluating diabetes influence on cochlear nerve conduction velocity before hearing loss occurs in these patients.

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Background and Aim: Dyslexia is the most common learning disability. One of the main factors have role in this disability is auditory perception imperfection that cause a lot of problems in education. We aimed to study the effect of auditory perception training on reading performance of female students with dyslexia at the third grade of elementary school.

Methods: Thirty-eight female students at the third grade of elementary schools of Khomeinishahr City, Iran, were selected by multistage cluster random sampling of them, 20 students which were diagnosed dyslexic by Reading test and Wechsler test, devided randomly to two equal groups of experimental and control. For experimental group, during ten 45-minute sessions, auditory perception training were conducted, but no intervention was done for control group. An participants were re-assessed by Reading test after the intervention (pre- and post- test method). Data were analyed by covariance test.

Results: The effect of auditory perception training on reading performance (81%) was significant (p<0.0001) for all subtests execpt the separate compound word test.

Conclusion: Findings of our study confirm the hypothesis that auditory perception training effects on students' functional reading. So, auditory perception training seems to be necessary for the students with dyslexia.

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Background and Aim: Conversational repair skills are essential for establishing mutually successful verbal communication. Cognitive and linguistic disorders can have negative effects on these skills. Children with hearing loss have special cognitive and linguistic issues. This study was performed to contribute to the paucity of data on conversational repair strategies used by hearing impaired children.

Methods: The participants included 58 children with moderate hearing loss (38 boys and 20 girls) aged 6 to 7 from Ahvaz city. A cross-sectional study design was used. Frequency of using different types of repair strategies in ten repair situations was calculated. Scores of intelligence, memory, word finding, lexical richness, and mean length of sentences was obtained through cognitive-linguistic tests. Data was analyzed employing an independent t-test, Pearson correlation coefficient, and logistic regression.

Results: A direct correlation was observed between clarification strategy and communicative social intelligence (p=0.045). A direct correlation was observed between applying different types of conversational repair strategies and linguistic abilities in children with moderate hearing loss (p<0.05).

Conclusion: Children with moderate hearing loss (age: 6-7 years) use repetition more than any other strategy to repair conversation. One unit increase in word finding ability or in mean length of sentence predicts one unit increase in the degree of using repetition strategy.