Originally Posted by Vortac180
. . .
When I decide to finally buy an ANR headset (if the 25 XT ever wears out, I guess), I'll strongly consider the Telex Stratus 30XT or the Telex Stratus 50. Both use a combination of active and passive noise reduction. Also, in the unlikely event that the battery runs out, you'd still have 29 db passive noise reduction. Not bad!
Geoff
All ANR headsets use a combination of active and passive noise reduction. For technical reasons, it's just about impossible to reduce high pitched noise with active reduction, so all ANR headsets actively attenuate only low pitched noise and depend on foam or other stuffing in the headset, just like non-ANR headsets do, to reduce the high pitched noise. This is of course still effective if the ANR fails for any reason.

Roy

States where I've landed my 150
[Linked Image from eznec.com]