this paper presents noise problems associated with the use of air-turbine drills in dental practice. two hundred and fifty dentists (male and female) were randomly selected from the faculty of dentistry as well as the dentists who worked private in tehran. the results indicated that the mean value of sound pressure level produced by the high-speed drills was 69.1 db. most of the energy from the...

[no abstract available]

OBJECTIVE To evaluate the improvement in speech intelligibility in noise obtained with an assistive real-time fixed endfire array of bidirectional microphones in comparison with an omnidirectional hearing aid microphone in a realistic environment. DESIGN The microphone array was evaluated physically in anechoic and reverberant conditions. Perceptual tests of speech intelligibility in noise we...

Introduction: One of the most important complications of exposure to noises is changes in the gene expression patterns. Irreversible damage to the inner ear, such as noise-induced hearing loss (NIHL), is caused by tissue damage and changes in the gene expressions in the auditory system. Changes in the GJB2 gene expression pattern lead to autosomal deafness at different loci. The present study a...

A total of 524 industrial workers were studied. They consisted of 442 noise exposed and 82 non-noise exposed workers. The purpose was to compare the prevalence of sensori-neural hearing loss among the noise exposed and the non-noise exposed workers, to study their knowledge on the hazard of noise to hearing and the workers' attitude towards the hearing protection devices. The prevalence of sens...

To reduce the surrounding noise in the hearing aids by using active noise control system. Background noise is particularly damaging the speech intelligibility for people with hearing loss. Background noise reduces the clarity in the speech. So we are able to understand speech in moderately in noise environment even at the sufficient signal to convey the information. There is less redundancy in ...

This paper presents noise problems associated with the use of air-turbine drills in dental practice. Two hundred and fifty dentists (male and female) were randomly selected from the faculty of dentistry as well as the dentists who worked private in Tehran. The results indicated that the mean value of sound pressure level produced by the high-speed drills was 69.1 db. Most of the energy from...

OBJECTIVE To determine the prevalence of hearing loss associated with occupational noise exposure and other risk factors. DESIGN A cross-sectional study involving 269 exposed and 99 non-exposed subjects (non-industrial noise exposed subjects) randomly selected. Current noise exposure was estimated using both sound level meter and noise-dosimeter. Past noise exposure was estimated by interview...