SENNHEISER HMEC 45-KA
Manual de Usuario

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® 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 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 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

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.