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Idiomas disponibles
Idiomas disponibles
Reduction of subjectively perceived noise level
are dynamic stereo headphones which, in addition to transmitting an
NoiseGard
™
audio signal, also electronically compensate low-frequency noise. This active noise
compensation functions according to the physical principle that noise and „anti-
noise" (exactly reversed in phase) cancel each other out.
So, now you can enjoy your music undisturbed, without having to turn the volume
up so high that surrounding noise is completely drowned out.
The
™
compensation electronics in the headphone requires its own power
NoiseGard
supply. This is provided by the power supply unit which is fixed to the cable.
The headphone is connected in the usual manner by a 3.5-mm stereo jack plug, by
an adapter to two 3.5-mm mono jack plugs (in aircraft) or by means of a 6.3-mm
adapter (to the hi-fi unit at home). Both adapters are supplied.
Noise compensation with NoiseGard
™
Attenuation in dB
Human speech
0
Reduction of the
subjectively perceived
noise level with
Noisgard
10
20
200
100
500
1000
8
HDC 451
8-9
Warning Signal
2000
5000
Frequency / Hz
HDC 451
NoiseGard
™
The first „open-air" stereo headphone with
At just 110 g, this „open-air" stereo headphone with active noise compensation is
extremely light and provides excellent wearer comfort. Sound coupling to the ear
is directly on the ear.
When you are wearing the
NoiseGard
™
in conversation - the voice of the person talking to you is scarcely changed,
since the speech frequency is practically unaffected by compensation.
Warning or emergency signals remain audible.
Understanding speech is even improved by
by low-frequency sound is eliminated.
Switching ON/OFF
ON/OFF switch for the power supply to the compensation electronics is situated
on the battery box. A green LED lights up as a check.
If the power supply is switched off or the batteries are worn out, the headphone
can still be used as a normal headphone without noise compensation.
Inserting the batteries in the power supply unit
12.07.2002, 13:21 Uhr
active noise compensation
NoiseGard
™
HDC 451 you will still be able to join
™
, as „upward-masking"
NoiseGard
ON/OFF
LED
9
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