Tests and assessment of efficiency of attenuating impulse noise with earplugs

Project manager: Jan Żera Ph.D. (Eng.)

Project summary:

This research task consisted in developing of a method and conducting tests of earplugs from the point of view of the efficiency of attenuating impulse noise. Two measurement stands for testing earplugs were developed. They are equipped with testers for testing earplugs and for testing double protection.This research task involved measuring impulse noise attenuation of 21 earplugs of 5 different constructions: foam earplugs, premolded Flanged earplugs, headband earplugs, cottonwool earplugs and wax earplugs. The measurement results indicated that, like in the case of earmuffs, attenuation of earplugs increases when the level increases and the time of the increase of external noise decreases at the same time.Special attention should be paid to the obtained protection against impulse noise when earplugs and earmuffs are used at the same time. Double protection increases attenuation by 20 dB in comparison with attenuation provided by earplugs, provided that the earmuff that is used has high attenuation properties.

Unit: Department of Vibroacoustic Hazards

Duration: 01.01.2002 – 31.12.2004