Noise Cancellation in Old BiPlane

What's wrong with buying a Bose aviation headset? About $1K US.

Eg.

Best regards, Spehro Pefhany

Not bad -- but this cancels the noise in to the headset speaker.

I am also looking for cancelation of the noise getting in to the headset microphone.

Regards joe

That is how the noise cancelling microphone works - it is open on both sides of the diaphragm so that ambient noise (almost) cancels.

You are asking for a solution to the holy grail of aircraft headset design. We've been after something to cancel microphone wind and engine noise for the last 50 years that I've been in the business. The closest we have come is a WWII design called a "throat mike". Look into it.

Jim

-- "It is the mark of an educated mind to be able to entertain a thought without accepting it." --Aristotle

When I was in the USAF (1968-1976) they had headsets that were like standard ear defenders, but with another piece that went over your mouth and nose. It had the same kind of noise insulation (basically, a hard plastic exterior and a bunch of soft foam inside) as the earthings, but I think you still kind of had to shout into it, and it was uncomfortable as hell.

But they _DID_ get the job done. ;-)

Cheers! Rich

Isn't it considered a sin in aviation to muffle that sweet sound of the big old radial engine up front? I enjoyed every second of it, including the oil splatters on the shirt. The owner had to then fly it back to Mariposa and I asked him whether the noise would go on his nerves during long flights. "Are you kidding? This is like music!"

Right. It gets on his nerves when it stops.

The problem isn't to muffle the engine noise to the pilot, but to the passengers if (s)he has an intercom OR on the aircraft radio which is nearly unintelligible with an open-cockpit aircraft.

Jim

Would such a system be useable to reduce PC supply fan noise?

Analog Devices has an app note on how to use a DSP to cancel fan noise.

JG

I loke the Throat mike idea.... what did it sould like? normal voice or much different.

Regards Joe

In the Stearman we did not have any problems with either and the gear was not the fancy Clarke stuff, looked like plain old military issue.

A little garbled but I don't think you could tell the difference. ;-)

Thanks.

I found out more... the BiPlane Pilot already has system using a mobile phone. with an audio patch circuit to a David Clark headset.

I will get the pilot to ring my land line (POTS PSTN) and record the iPlane - while he is talking to me and without any talking..

I'll record it using Opensource (free) Audacy software on a PC.... then do a audio spectrum plot to see if we can notch out the noise.

I aleady have a telephone interface circuit that plugs in tp the microphone of the PC...

Joe

iPod, iPhone, iPlane ? Finally Apple must have come out with something really useful. Cool! I wan't one :-)