[Doug Freyburger]

Les Cargill wrote:
RichD wrote:

A noise canceling headphone consists of a headphone,
plus an external microphone fed to an inverting input,
right?

There's more signal processing involved than that.

Why does that cost $40 extra?

2) Because that is what people will pay for them.

In particular they perform a very valuable function. Many people big
distracted by background noise so they can work under more
circumstances. Some people are bothered by certain noises and can't
sleep. There's a long list of such applications.

Guy I went to college with went to work for Evil Corporation "X", and
basically lived on the road for like ten years. Wasn't married, so
he was able to save almost everything he made. The point is that these
are a "travel" item and people who burn through a corporation's travel
budget can offset salary & bonus with such purchases, and the
resulting value to them is higher than for those of us who don't.

There's a guy at the office who wears noise cancelling headphones to be
able to work. He's the second loudest guy in the office when he's not
wearing them but quiet when he's wearing them so everyone benefits.
Well, almost everyone. The reason he wears them is his cubicle is close
to the first loudest guy in the office who's on a completely different
scale than most people. The headphones are literally called "Brian
cancelling headphones" in this case.

That is why the Sky Mall magazine is like it is...

The prices aren't that different in stores for many of their items.