The Problem of Noise
The negative effects of noise pollution have been proven by studies, and everybody will have experienced them at some time or another:
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™ system, Sennheiser has come up with an effective solution. These operating instructions explain the NoiseGard™ principle and show you how to use the NoiseGard™ headset.
Noise levels
| 140 dB | Jet engine (at a distance of 25 m) |
loud | 130 dB | Aircraft engine (This is the treshold of pain) |
120 dB | Pneumatic drill | |
| 110 dB | Blacksmith's hammer, concrete works |
| 100 dB | |
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| 90 dB | Metal workshop |
| 80 dB | Tractor |
| 70 dB | Office |
| 60 dB | Conversation |
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| 50 dB | Ambient noise |
| 40 dB | Living room |
quiet | 30 dB | Library |
20 dB | Bedroom | |
| 10 dB | Forest, no wind |
The unit of sound levels is the decibel (dB). A noise reduction of 10 dB is generally perceived as a halving of the loudness, another 10 dB decrease halves the loudness yet again whitch corres- ponds to a loudness reduction of 75 %, and so on.
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