The influence of frequency component content on the selection result of hearing protectors.

Hearing protectors are selected for workstation noise using the octave band (OB), HML and SNR methods. The purpose of this study was to determine how the frequency components of the noise can affect the selection of hearing protectors. In total, 55 hearing protectors were selected for four types of real occurring noise, high-frequency noise, low-frequency noise and eight simulated noises. Analysis showed that the noise type affects the accuracy of selection carried out using the HML and SNR methods. For a noise with dominant frequency components, the result for selection carried out using the HML method deviates from the result using the OB method by 7 and 9 dB for earmuffs and earplugs, respectively. The study shows that use of the HML and SNR methods may lead to wrong assessment of the effectiveness of hearing protection with the selected hearing protectors.