Digital Adaptive Noise Reduction Danr - Beyerdynamic HS 800 Digital Produktinformation

1. Original noise
The active noise reduction is especially effective in the deep frequency range (25 to 500 Hz).
With higher frequencies it is less effective. This is the reason why a headset often provides a
combination of active and passive hearing protection.
3.2

Digital Adaptive Noise Reduction DANR

Active noise reduction on an analogue basis for Aviation headsets has been existed for more than
20 years. A headset with analogue active noise reduction starts working after switching it on.
The properties of the analogue filter always remain the same independent on the acoustic
surrounding. Therefore, an analogue active headset cannot adapt to modified acoustic situations.
This applies the advantages of the digital signal processing. The NC filter has been programmed
as a software algorithm and processes digitalised audio signals on a micro processor. In addition
to a more precise result the main advantage is, that it intelligently reacts to various acoustic
surroundings. This includes an automatic activation when the engine is started and an adaption
to peaks, which are typical for engine noise. An analogue NC filter cannot differ between very
loud and quiet frequencies.
Note:
As DANR is activated automatically when the engine is started you will not notice any
noise reduction and background noise when the DANR function is activated with
normal ambient noise. You can check the DANR function when you deactivate the
DANR function during the flight.
2. Audio signal with
inverse wave shape
– phase inverse
3. The original noise is
superimposed by
the phase inverse
audio signal and
reduced: The ear
drum receives less
noise.
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