6
Noise - can we ever escape it?
At work, at home, in public transport, on ‘plane, train or bus journeys - noise is with
us wherever we go.
Studies have verified the negative effects of noise, and every one of us will have
noticed them at one time or another:
왘
Nervousness
왘
Lack of concentration
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Irritability
These are only the obvious effects on the human organism. Noise also affects the
vegetative nervous system, and can permanently damage the hearing.
The sources of noise are many and diverse and, all too often, cannot simply be
turned off. So, in noisy places, personal protection is the only remedy.
With the
NoiseGard
®
mobile
system, Sennheiser have come up with an effective
solution. These instructions explain its functioning principle and operation.
Sound level of noise sources
140 dB
Jet engine (at a distance of 82 ft)
130 dB
Aircraft engine
120 dB
Pneumatic drill
110 dB
Forging hammer, concrete works
100 dB
Metal die-casting machine
90 dB
Metal works
80 dB
Tractor
70 dB
Office
60 dB
Conversation
50 dB
Environmental noise
40 dB
Living room
30 dB
Library
20 dB
Bedroom
10 dB
Forest, no wind
SOFT
LOUD
The unit of measurement is the decibel (dB). A noise reduction of 10 dB is generally perceived
as a halving of the noise level. If the noise is reduced by a further 10 dB, this is perceived as a
75% noise reduction, and so on.
