wrote:
>
>I am trying to decide on an Active Noise Reduction (ANR) headset or
>earplugs. I have looked at the Sony, Bose, Shure and other models, but
>almost all reviews/comments mix two very different issues: noise
>reduction and sound quality.
Why not use both at the same time? It is fairly standard practice to use
foam plugs underneath active ear protection devices.
>In my case, I have no interest whatsoever in sound quality, what I am
>looking for is the absolute best noise reduction possible. I have
>tried the Bose Quiet Comfort II, and they appear extremeny effective,
>but only in the middle-low frequency range. Also, I have a feeling
>that ANR earplugs might be more effective.
For the most part, none of the active noise reduction systems work much
above 1 KHz or so.
My feeling is the Sennheiser pilot headsets are definitely better in an open
cockpit plane (lots of repetitive impulse noise) than the Bose pilot ones.
The consumer (open ear) ones are all pretty lousy.
>Various manufacters claims various degrees of noise reduction. As for
>Bose, they do not even release their technical specs (although would it
>not be possible for any lab to measure them across a frequency range
>and publish the results?).
That's the way Bose is. Bose products are 90% marketing, and 10% technology.
Some of them (like the headsets) work okay, just at much higher cost than
they should. If you look at the over-ear Bose sets for pilots, though,
they will have some minimal specifications on the data sheet.
>Recently I met a guy who was working in the US Navy on the deck of
>aircraft carriers. He said that the headsets they had cancelled out
>everything, that nothing could be heared at all when he was wearing
>them. Since this hardly constitutes a secret technology, is it known
>who designs these headsets for the US Navy? Is this technology used
>for the civilian market by some manufacturer?
These are over-ear earcup devices. The high frequencies are blocked out
mechanically, the low frequencies are blocked out with active noise
cancellation. You can then use foam earplugs underneath them for additional
high frequency cancellation.
This is typical of the David Clark ground support sets:
http://www.davidclark.com/HeadsetPgs/h3530.htm
You'll notice that the David Clark website gives actual measured attenuation
numbers across the band, rather than made-up crap or single-frequency
marketing numbers like Bose shows.
>Can anyone give me some pointers as to how I could go about finding the
>best ANR headset/earbuds out there?
Your deck crew guy is probably issued a set of David Clarks. Sennheiser
also makes some that are okay.
The big question is what kind of noise you're trying to block out. If
you're sitting in a 747 or a Stearman, the noise patterns are very different.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis." |