نتایج جستجو برای: acoustic noise measurement
تعداد نتایج: 694467 فیلتر نتایج به سال:
background acoustic trauma is an injury to the hearing mechanisms in the inner ear due to excessive noise. this injury is the most prevalent cause of sensorineural hearing loss in humans, especially from occupational exposure. previous studies have shown the essential role of free radical formation in the inner ear hearing loss caused by acoustic trauma. objectives this study was performed to d...
Introduction: Persecutors of aircraft noise at an airport has a close relationship with the alternate of landing and take-off weight of the aircraft and operations planning during the night. Now aircraft that spill in Yazd airport and take-off of aircraft is of jet engines or so-turbofan mean that the resulting sound will be very high. Methods: In this descriptive, cross-sectional me...
Abstract: Background and aims: Using water pump in residential buildings to provide the required water pressure is accompanied by noise pollution and the annoyance of residents. So, the purpose of this study is to reduce water pump noise pollution with designed acoustic curtains in a residential building of Qazvin city. Methods: The mean sound pressure level was measured before and ...
This study evaluates the impact of underwater ambient noise using seven real noise samples; Dolphin, Rain, Ferry, Sonar, Bubbles, Lightning, and Outboard Motor in three frequency ranges in extremely low frequency (ELF) band. The ELF band is the most significant bandwidth for underwater long-range communication. ELF band which is extended from 3 to 3000 Hz clearly, faces bandwidth limitation. Me...
ارزیابی عملکرد آکوستیکی مانکن سر جهت استفاده در آزمون های تعیین قدرت کاهندگی صدای وسایل حفاظت شنوایی
Introduction:One of the recommended methods for evaluation effectiveness of hearing protection is use the acoustic fixture accordance with standard ISO 4869-3. The aim of this study was evaluate the acoustic performance of fixture for using in noise reduction rate tests of hearing protection devices in the laboratory. Methods: In this cross-sectional study , noise reduction rates o...
the equivalent noise level in large cities has been growing due to the population growth, uncontrolled production of cars, and the existence of worn out cars. on the other hand, heavy traffic has increased the amount of noise problems for residents of medical and educational centers, research institutes and residential area (or sensitive centers to noise) built in highway bounds and it has also...
Objectives: The present study aims to compare acoustic voice parameters in patients with vocal cord nodules, polyps, and normal subjects. Methods: In this cross-sectional case-control study, the participants were selected by convenience sampling, including 30 patients with vocal polyps group, 38 patients with vocal nodules for the second group, and 42 participants without voice pathologies a...
This paper summarizes a case study example on the methodology used for phased array microphone measurements in a realistic acoustic environment. A ducted fan rotor is measured in an environment, where structure born noise and aerodynamically generated noise cannot be separated using conventional single microphone acoustic analysis. The conditions of the measurement are similar to an industrial ...
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