SW Version 3.03 date 03.12.2012
14
Basic Hearing Information
Overview of different noise levels
20 dB
rustling leaves
40 dB
in living room with windows closed
60 dB
conversation
70 dB
open plan office
85 dB
medium traffic noise
95 dB
heavy-vehicle traffic
100 dB
jack-hammer
110 dB
rock or pop concert (at some distance from the stage)
125 dB
starting jet plane at a distance of 100 m
130 dB
pain threshold
140 dB
jet plane at a distance of 25 m
It should be taken into consideration that a doubling of the power supplied (to an
amplifier) corresponds to an increase in noise level of 3 dB. However, the human ear
only registers a doubling in volume at an increase in the noise level of 10 dB. Damage to
hearing is dependent on the noise level and damage commences long before the pain
threshold is reached!
Many people make the mistake of imagining that noise is something that you „get used
to“. There is no point arguing against the assertion that a positive attitude towards a
particular sound can lessen physiological reactions. However the lingering effect on the
inner ear is an entirely different matter: the overstimulation and gradual disintegration of
the hair cells in the organ of corti.
Subjectively the degradation in hearing is perceived as if the ears were “packed in cotton
wool”. Often there is a quick recovery of the hairs, however, some loss in sensitivity of
hearing generally remains.
In order to ensure appropriate recovery of hearing, the noise level should not exceed 70
db(A) for a period of at least 10 hours. Significantly higher sound pressure levels during
this rest period can make recovery more difficult and can make it more likely that
permanent reduction or damage to hearing occurs.
Therefore, on the basis of this information: protect your hearing and that of your
customers!
