[Arny Krueger]

"GoodFella" wrote in message
lkaboutaudio.com

Hi there, what is the working principle behind noise
canceling headphones?

A microphone picks up ambient noise near the headphones, inverts it and
mixes it with the normal input signal.

Since the noise is inverted, it cancels with noise that leaks into the
headphone through the air.

Do they all use the same mechanisms?

Same basic idea, differences in how they refine the idea.

Which ones would you recommend as best in
terms of actually canceling them outside noises, as
opposed to audio quality?

None of them. I favor using in-ear monitors (IEM), that block out outside
noises.

The problem I have is that I am once again going to
embark upon a series of business trips, to the US,
Malaysia, Japan, etc. Lo-ong flying hours... I need to
shut down that airplane noise. OTOH, there is a big new
construction right next to our office that will last
some months, if not years, damn it... Lots of
hard-pressed diesel engine grunts creeping into my
office... So it's the other criteria that I am after that
the device is able to counter such noises also.

IEMs are cheap and effective. The better low cost models like the Sony
MDR-EX71 (under $20) at worst will give you a good idea of how they work and
whether you can tolerate them.

Any help would be much appreciated.