Sennheiser NoiseGard HMEC 45-CA Instructions For Use Manual page 2

The problem of noise
The negative effects of noise pollution have been proven by studies, and everybody
will have experienced them:
Nervousness
Lack of concentration
Irritability
And these are only the most obvious effects on the human body. Noise also affects
the autonomic nervous system and can lead to permanent hearing damage.
There are a multitude of noise sources, and the individual very often has no
influence over them. The only solution when being in a noisy place is protecting
oneself against ambient noise. These noise problems are particularly prevalent in
an aircraft cockpit where a pilot often has to have the communications headset so
loud as to risk permanent hearing damage.
With the
NoiseGard
These operating instructions explain the
to use the
NoiseGard
Noise levels
loud
quiet
The unit of sound levels is the decibel (dB). A noise reduction of 10 dB is generally perceived as halving of
the loudness, another 10 dB decrease corresponds to a loudness reduction of 75 %, and so on.
system, Sennheiser has come up with an effective solution.
®
headset.
®
140 dB
130 dB
120 dB
110 dB
100 dB
90 dB
80 dB
70 dB
60 dB
50 dB
40 dB
30 dB
20 dB
10 dB
NoiseGard
Jet engine (at a distance of 25 m)
Aircraft engine (This is the treshold of pain)
Pneumatic drill
Blacksmith's Hammer, concrete works
Die-cast machine
Metal workshop
Tractor
Office
Conversation
Ambient noise
Living room
Library
Bedroom
Forest, no wind
principle and show you how
®