Guy Alcala wrote:


Without knowing how directional the in-mask mikes are, or their noise-cancelling
qualities/frequency characteristics, I'm not qualified to comment so I'll happily
defer to you on that point, although you've said that you used handheld rather
than throat or in-mask mikes. My only personal experience is with modern headset
mikes, which do indeed elminate most if not all of the engine noise (albeit a far
less powerful, single or dual piston engine).

Guy

Yes indeed, those modern noise cancelling mikes are great, I
think some use sort of a feedback 'out of phase' of ambient noise
to cancel the noise, they work great but no such niceties were
available to us. We did (for the most part) use carbon hand held
mics but had carbon button mics inside the oxy masks for high
altitude ops. Most of us found them so muffled that we'd just pop
one side of the mask off to use the hand mic for a few secs.
--

-Gord.