Introduction: noise pollution has a negative effect on physiological parameters, efficiency and auditory system. The aim of this study was to evaluate the performance of a sound screening method for estimating sound risk in small workshops of Hamadan city. Methods: This cross-sectional study was conducted in 22 plants with more than 20 workers. Noise screening was done using a screen...

    Background and aims  The influences of Low Frequency Noise (LFN) on mental performance have been the objectives of many papers in recent years. Many researchers believe that the LFN even at low pressure levels has impacts on mental performance. In the present work the influences of LFN and Reference Noise (RN) at two different sound pressure levels (45 & 65 dBA) on mental performances of co...

The Research has shown that the primary sound source in centrifugal turbomachines is the blade passing frequency noise, which is caused by due to impac rotor exit flow with the volute and the wild pressure fluctuations. In this paper, a centrifugal blower with forward facing blades has been selected and the sound created by it in the output channel has been investigated in different operating c...