65 Hearing protection Our hearing is a valuable, sensitive sense organ. Hearing is a matter of course for most people. But noise-induced hearing loss rarely happens overnight. It builds up over time by any unprotected exposure to dangerous noise levels. This is why appropriate hearing protection must be made available from 80 dB(A), as irreversible damage to the sensitive auditory cells is possible from this point. Wearing hearing protection is mandatory in the workplace from 85 dB(A). Noise examples 120 - 130 dB(A) jet engine, pain threshold 110 - 120 dB(A) thunder storm, pneumatic hammer 95 - 110 dB(A) disco music, chainsaw, express train 85 - 95 dB(A) telephone rings, lorries, hearing protection prescribed in the workplace from this point 70 - 85 dB(A) bike bell, TV, lawnmower 50 - 70 dB(A) sewing machine, group conversation, office noise 30 - 50 dB(A) quiet music, normal conversation, rain 0 - 30 dB(A) leaves rustling, whispering, fridge humming An increase of 10 dB is perceived as a doubling of volume. SNR value (simple insulation value) – the value indicates how many decibels the hearing protection reduces the noise by (example: headphones with 30 dB SNR reduce the volume from 90 dB to 60 dB).