But as long as I'm here: there is a tradeoff between what is "noise" that
can cause permanent high frequency hearing loss and blocks out necessary
sounds and the sounds that we must hear in normal conversation and
maintaining awareness of what sounds mean what and from where. Remember
that we can locate where sound is coming from (a part of good SA), except
when we are wearing a headset which attenuates too much sound. The best
solution is still to wear ear plugs, the "EARS" type, and if necessary a
good but not complete "noise" attenduating headset. The other problem is
the definition of "noise", and again that's defined in "noise--good", etc.
Dick (USAF/FS, SrAME)