Originally Posted by
SuperF
I wish i could figure it out, but i just swap between ANR and CEP helmet, depending upon what helicopter I'm going to fly, and what I'm doing.
As senior pilot says, this has been discussed many times. In the military case I mentioned (RN Sea King AEW Mk2), in 1994 the RN specifically rejected in-ear devices, which were the initial proposed solution.
But to your problem SuperF, depending on what type of ANR it is, it may be unrealistic to expect it to work in an aircraft it is not designed for. The Sea King ones were good for ASW and AEW variants, but not for the Mk4. Purely by coincidence, they worked in Sea Harrier. They were hopeless in Lynx, not too bad in Merlin but only for rear crew. Just minor component value changes to target the damaging frequencies in different aircraft, and let the frequencies you need to hear through.
At the most cheap and cheerful level, you can be sold a broadband system such as that used in the back of armoured vehicles. They don't have to worry about what you need to hear, and blot out most noise. The one above is the analog system, designed to meet the then 85dBA requirement. (Around 83 achieved). You needed a noise survey in each aircraft type/mark, and from that a variant of the PCB was developed. You either had a second helmet, or spent an hour changing the capsules. (And there has to be the same power source/connector). In the military, ANR presents a further problem - the helmet is no longer just an Aircrew Equipment Assy, it is a Comms System LRU, as it is aircraft powered and sits inside the TEMPEST boundary. And the associated curly leads were far more expensive that the ANR helmet.
Concurrently, a Digital ANR was developed to meet the new 75dBA requirement, and by 2000 had achieved around 71dBA. ISD was due 2001, but I'm not sure what happened as I was gone by then. That was programmable, so if you wanted to fly a different type one day, you simply plugged the helmet into a workstation and blew the EPROM for that aircraft. The next development milestone was adaptive ANR, which aimed to negate all that faff. I know it was successful - the same team at Farnborough did it - but don't know how widely it is used.
The answer to your problem is not straight forward, but hopefully I've given a few pointers on what to ask of your supplier.
I won't comment on Bose and ANR!