نتایج جستجو برای: sound pressure level
تعداد نتایج: 1531055 فیلتر نتایج به سال:
excessive exposure to noise can lead to noise-induced hearing loss. otoacoustic emissions affect the microscopic biomechanical activities of healthy outer hair cells. the present study aimed at assessing the influence of various sound pressure levels on distortion product otoacoustic emissions (dpoaes) in rats. to this end, 27 adult male rats with an age range of 3 to 4 months and a weight of 2...
Background and aims: High levels of noise that most operators of agricultural machinery are exposed to for a long time contribute to cause chronic fatigue and irreversible hearing loss. For this reason, occupational health and safety issues related to such machinary should be considered as a key criterion in the design of agricultural machinery and as a critical factor in the acceptance and sal...
INTRODUCTION The use of Personal Digital Audio Players can cause hearing injuries, as the sound is generated directly in the ear canal. It is believed that different types of headphones can cause different amplifications, since they cause changes in the volume and resonance of the ear canal according to their depth. OBJECTIVE This study aimed to determine the sound pressure to which young ind...
background: noise is one of the most important harmful agents in work environment. noise pollution in oil refinery industries is related to workers' health. this study aimed to determine the overall noise pollution of an oil refinery operation and its frequency analysis to determine the control plan for a vent noise in these industries. methods: this experimental study performed in control unit...
Background and Objective: Noise pollution is one of the serious environmental issue. Sound control technologies based on sound absorption and sound insulation are considered as the two widely used methods. Therefore, the aim of this study was to modify silica aerogel nanocomposites to improve its acoustic properties. Materials and Methods: This applied experimental research involved in examin...
Introduction[N1] :One of these annoying stimuli and a major source of stress in the NICU is sound. In neonatal intensive care units, sounds with different intensities and frequencies are produced from different sources such as fan devices, intermittent alarms, ventilators, telephones, door opening and closing, and staff conversations; Studies have reported that the average noise level in the NI...
AIM To evaluate the sound pressure level to which preschool students are exposed. METHOD This was a prospective, quantitative, nonexperimental, and descriptive study. To achieve the aim of the study we used an audio dosimeter. The sound pressure level (SPL) measurements were obtained for 2 age based classrooms. Preschool I and II. The measurements were obtained over 4 days in 8-hour session...
Background and purpose: Noise is one of the most harmful factors in the environment. It is also one of the harsh phenomenons in this century that people are exposed to. Exposure to noise higher than threshold limit value could cause some physical and mental disorders. High traffic flow due to recent increase in number of vehicles causes higher noise pollution. There are few studies regarding ...
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