ANR Headsets and Open Intercom.
Thread Starter
Joined: Dec 1998
Posts: 96
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From: Down Under
ANR Headsets and Open Intercom.
Has anyone else had the experience that when wearing an ANR headset with a hot intercom in 2 crew operation that you still get so much noise. Switch the I/C 'off' and it's silent 
, so I conclude the noise must be comming from the 'other' headset mike. Switch the I/C back 'on' and back comes the noise 
. Sort of defeats the purpose of having an ANR headset in the first place, it would seem. Is there any solution that you know of whilst leaving the I/C 'on' ?
First impressions are that there are not too many technicians who realy have in depth knowledge of these new ANR heasets and can therefore do some appropriate troubleshooting.
, so I conclude the noise must be comming from the 'other' headset mike. Switch the I/C back 'on' and back comes the noise . Sort of defeats the purpose of having an ANR headset in the first place, it would seem. Is there any solution that you know of whilst leaving the I/C 'on' ?First impressions are that there are not too many technicians who realy have in depth knowledge of these new ANR heasets and can therefore do some appropriate troubleshooting.
Joined: Aug 2003
Posts: 190
Likes: 1
From: Earth
Tend to get a similar problem with the Intercom volume turned up high perhaps it's more noticable with the ANR headsets. My only suggestion is to try and turn down the I/C volume as there seems to be a point with the type I'm flying where the background noise leaps up.
It's always struck me as strange that there is no Squelch function on the intercom
It's always struck me as strange that there is no Squelch function on the intercom
Joined: Nov 2004
Aviation Qualifications: ATPL
Posts: 620
Likes: 136
From: UK
ANR headsets can only cancel acoustic noise which would otherwise have reached the ears from the environment. They simply cannot reduce the 'transmitted' noise from the other microphones on the system which is fed to them electrically. A headset cannot make the distinction between wanted signal, for example speech, and unwanted signal like the microphone noise.
That you notice the microphone noise so clearly on your ANR headset is a tribute to the acoustic noise cancellation being achieved by the headset. Without the ANR, the mic noise would be masked to the point where it blends into the other ambient acoustic noise.
In your case, possibly the best solution would be to prod the other pilot to switch off his mic and then you ought to be able to enjoy the full benefits of ANR tranquility.
In audiophile circles it is often found that upgrading one component of an audio system gives a worse sound than before; as the saying goes 'The wider the window is open, the more !!!! flies in'. In other words, by upgrading for example the loudspeakers to a more revealing pair, it often allows you to hear the faults of the rest of the system, CD player, amplifier etc, which were thankfully masked by the rubbish speakers before.
To give an extreme example, as you become progressively more deaf with age, even the cheapest, nastiest boom-box stereos start to sound as sweet as the most expensive hi-fi, saving you fortunes of wasted cash!
That you notice the microphone noise so clearly on your ANR headset is a tribute to the acoustic noise cancellation being achieved by the headset. Without the ANR, the mic noise would be masked to the point where it blends into the other ambient acoustic noise.
In your case, possibly the best solution would be to prod the other pilot to switch off his mic and then you ought to be able to enjoy the full benefits of ANR tranquility.
In audiophile circles it is often found that upgrading one component of an audio system gives a worse sound than before; as the saying goes 'The wider the window is open, the more !!!! flies in'. In other words, by upgrading for example the loudspeakers to a more revealing pair, it often allows you to hear the faults of the rest of the system, CD player, amplifier etc, which were thankfully masked by the rubbish speakers before.
To give an extreme example, as you become progressively more deaf with age, even the cheapest, nastiest boom-box stereos start to sound as sweet as the most expensive hi-fi, saving you fortunes of wasted cash!
Joined: Feb 2007
Posts: 390
Likes: 0
From: Scotland
Indeed. That's the solution. Initially it picks up a tremendous amount of static noise when you open the intercom. Highly distracting and annyoing.
All you need to do is just adjust the GAIN. Open the intercom and with a small screwdriver from a sewing kit or so and turn the GAIN down. You'll usually find a very small opening under the mic muff. Doing it this way gives you a good idea of the peace and quiet afterwards. I only found this out after using it online for one year. Now I sometimes find myself going for the intercom open switch when in fact it's already open. That's how much difference there is!
I also noticed that on some of our aircraft there's more background noise than on others. It also varies a tiny bit by what headset the other guy is using.
P.S. I use my own Sennheiser HMEC 25KA(S) ANR Headset and am really pleased with it.
All you need to do is just adjust the GAIN. Open the intercom and with a small screwdriver from a sewing kit or so and turn the GAIN down. You'll usually find a very small opening under the mic muff. Doing it this way gives you a good idea of the peace and quiet afterwards. I only found this out after using it online for one year. Now I sometimes find myself going for the intercom open switch when in fact it's already open. That's how much difference there is!
I also noticed that on some of our aircraft there's more background noise than on others. It also varies a tiny bit by what headset the other guy is using.
P.S. I use my own Sennheiser HMEC 25KA(S) ANR Headset and am really pleased with it.
Joined: May 2005
Posts: 224
Likes: 0
From: UK
This type of noise reduction works using the input from the headset's own microphone - it is a self-contained system. What ever comes in from the microphone has noise reduction applied to it i.e. wing/engine noise etc. If you introduce another signal that does not come from the microphone it will not be processed and therefore will be heard. This is obviously desirable with intercomm and radio.
