Evaluation of Environmental Noise Control at a Press Workshop of a Metal Structure Factory using the ISO 11690 Method

Noise absorber is considered as main method for noise control based on noise propagation in indoor workrooms. This study aims to evaluate the effectiveness of environmental noise control using noise absorber at press workshop based on ISO 11690 method.

This experimental study was performed at press workshop of the metal structure company in 2019. The environmental noise control is installation of metal mesh using perforated gypsum tile with a layer of stone wool at the press workshop ceiling. Intervention evaluation was performed based on ISO 11690 method which is included determination of the rate of noise spatial decay from omnidirectional source based on distance doubling. The noise level was measured at the defined distance from an artificial noise source along the length of the workshop.

The environmental noise was reduced approximately from 3 to 4 dB after installing an acoustic ceiling. These noise reductions were considerable at the frequency spectrum of 2000 Hz, 4000 Hz and 8000 Hz.  Based on distance doubling, noise spatial decay of 4 dB from omnidirectional source was observed so that it represent a reduction in the surface noise reflections of the press workshop and consequently, environmental noise reduction.

The efficiency of environmental noise control was determined with high accuracy using noise spatial decay curve from omnidirectional source and compare it’s with the recommended optimal conditions and with the free field noise propagation curve.