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Anyone have definitive knowledge about the effects of 'Active Noise Reduction'? The out of phase signal is an equal and opposite frequency of the ambient noise, to neutralize the noise.

 

Does that mean that it sends the same harmful vibrations to your eustachian hairs while tricking you into thinking that you are recieving no amplifications?

 

Looking into buying something new to protect my ears!

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lineworker, i bought a David Clack x11 ANR headset last year when I started flying. The active cancellation is awsome, it mutes out quite a bit of the engine noise. The problem with most ANR headsets is that they have very little passive cancellation. As you were saying, yes the ANR is basically shifting/matching the sound wave frequency to make it seem to your ears that all is quiet. The down side to ANr, which I am just beginning to notice, is that the harmful waves are still getting to my ears, (whether you can hear it or not) and I can now notice a bit of a hearing problem developing due to the inadequate hearing protection provided by my ANR set. Im kicking myself now for not getting a headset with more passive cancellation. Basically what im trying to say is that even though all seems well with the ANR, the passive cancellation provided is insufficient to properly protect my hearing.

 

hopefully some of that made sense.....i kinda started to ramble :P

 

Cheers,

 

TM

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I actually wrote Bose about that question, twice the noise hitting your ears, but they replied that the signals are out of phase so cancel each other out. The end effect is indeed quiet, but I started to notice crickets chirping off in the distance whenever it got really quiet, like sleeping at night, a sure sign of some hearing damage.....could it be from wearing the Bose X for a year, or because I play guitar in a band???? Things do get loud so I generally play with hearing plugs, but even the chance that it was the Bose lead me to stop wearing it.

 

A friend recently advised these things, from

 

www.cep-usa.com

 

CEP%20with%20eartips.jpg

 

They run around $100 to $130, take about 30 minutes to install in a helmet (and involve drilling a small hole in the shell - see website) but the results are amazing.

 

They are basically ear plugs with tiny walkman-like speakers that tap into the signal coming into your helmet at one of the earphones, I think the US Military have adopted them for all flyers in noisy enviroments.

 

First day I had them, I did find some discomfort, as opposed to not having somehting jammed in your ear, but after the first hour I hardly noticed them, and that first day I spent 8 hours of flying in a noisy Super Puma, next day 7 hours. I actually took them out of 10 minutes to compare and quickly put them back in. They are not for everybody as some really don't like having ear plugs in (you can get custom shaped ones) but they are far quieter than any ANR system I've tried. It makes for very relaxed flying. The signal coming to your ear is unhampered by external noise and I've never heard clearer radio comms in my life. Very highly recommended.

 

I got the Navy issue mini-plugs, a few bucks more than the standards but smaller and more comfortable.

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Totally agree about the cep's, I've been through two pair now, and that's the problem. Unfortunately for me the wire into the transducer has seperated and broken on both pair within an 18 month period they are warranteed but thats not of much immediate benefit when you are at the beginning of a tour.

 

Could it be the user, I suppose. Even being as careful as I possibly could when using them I would occasionally forget to unplug them and give the wires a bit of tug when taking my helmet off. They were so comfortable that I'd forget I was wearing them.

 

Lineworker If memory serves correct the US Navy did a study on the effects of ANR at one time. It raised concerns over the total sound wave pressure within the earcup blahdeeblah... I stumbled across it online it might still be available.

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Phone an audiologist and ask for yourself.

 

I spoke with and College Audiology Instructor yesterday and he said they're fine. He said they CANCEL the noise and if you can't hear it, then it doesn't do any damage. 10 + minus 10 is Zero. Thats how he put it.

 

If you're using Bose, then the provide very little passive protection which doesn't help, even if they are comfortable.

 

ANC or ENC or whatever you want to call it, works best on low frequency noise and isn't as helpful when it comes to blocking noise from a turbine.

 

I have one of those cheap ANR kits ($200) and its useless in the 206. Nice in the Robbies, but I turn it off and use ear plugs in the turbine.

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Hope this may help some people out there.

 

CEP-USA

Ben Mozo

PH: 334-347-1688

 

He will be more than glad and very helpful in talking with you about the CEP system.

 

You can get Custom ear pieces specific for the CEP ( Westine Labs- 719-540-9333 John Spatafora )or Foam pieces for your ears ( supplied by CEP).

 

I have an Alpha Eagle, and they and Bladestrike recommended the same part #:

CEP- 104- K04E Navy Mini Cep. Smaller and more expensive, but apparently better. $ 120.00 US.

 

I have been looking at the CEP b/c I hear (lol) only great things from the guys who were them, and as with all, they have tried all different types of hearing protection for the loud helicopter.

 

Presently, I have Custom Silicon Vented from www.protectear.com now with the Hush Kit and Gel ear seals. Works good, but I turn up the volume. that ok for us as we have 2 comm boxes, so it effects no one else but me. Different if sharing a comm box with a customer.

 

There is a lot of info on here, just do a search and you will be amazed. This topic comes up from time to time.

 

Hope this helps someone.

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