[WARC] Nic Net Tonight!

[Leslie Hittner]

What kind of "noise" do noise cancelling headphones eliminate?
These devices integrate noise over time and eliminate the noise
by producing out-of-phase counterparts and linearly adding the
two waves. That means they are most effective on stable noise
sources, such as jet engine noise in airliners, components of
vehicle road noise, etc. They are less effective on short
duration pulse noise and sounds whose spectra vary with time
(like speech.)

In addition to the electronic noise elimination, noise canceling
headsets usually feature very effective acoustic isolation from
outside noise sources. I suspect such isolation, rather than the
electronic DSP systems, is most effective in communications
center environments.

I admit, I haven't listened to every noise canceling headset on
the market, but this has been my experience. I actually decided
not to purchase a pair but then I just got one from my son for
Christmas. My experience with that set so far bears out my other
observations and I believe I will most often use the headset
when flying.

I know that Clare has a set of noise canceling headphones and
would be interested in his observations, since I was unable to
be in the net tonight.

-Les

----- Original Message ----- 
From: "Len Litvan" <Litvan at acegroup.cc>
To: "W0NE Listserv" <warc at lists.w0ne.org>
Sent: Sunday, December 30, 2007 21:32
Subject: [WARC] Nic Net Tonight!


> Hi folks,
>
> That was a good net tonight--very informative.
>
> I especially liked the info about noise-canceling headphones.
I was
> about to buy a conventional headset (to replace the Radio
Shack and
> assortment of other earphones around) but was not considering
noise
> canceling types.
>
> The comments about noise canceling at emergency sites was a
big factor
> in persuading me to go upscale and get a noise-canceling set.
Thanks
> for helping me spend our money wisely!
>
> 73,
> Len KC0RSX
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