[TriLUG] VOIP soft phone help.

[Thomas Gardner]

On 8/18/12, Joseph Mack NA3T <jmack at wm7d.net> wrote:
> On Sat, 18 Aug 2012, Thomas Gardner wrote:
>
> I expect you'll get echo.

Hopefully, I'll find some SW that helps that, otherwise I'll just have
to try to minimize it by fooling with physical placement.

>                           Maybe you could have one mike
> capture the input channel and mute the others. I don't say
> this is easy.

Well, it would also kinda defeat the purpose.  Really, all the
microphones kinda have to be live in this application.  Unless what
you mean is that the first one to pick up up a sound manages to mute
the others.  That sounds like it would be a viable solution, but
that's kinda why I was writing to this list.  I was hoping someone
on the list might know of some SW that can do that fairly easily.

> You asked if you could cancell the TV etc. Noise cancelling
> headphones work by having the cancelling mike physically
> close to the speaker in the headphones. I expect you can
> only cancel for frequencies for which the phase difference
> is small, ie for frequencies below where
> lambda/4 > distance from mike to speaker headphone

I always thought that noise cancellation basically only canceled
out constant droning type noise (like a machine or fans or an engine
and the like).  I thought whatever changed pitch a lot and quickly
(like music and speech and whatnot), it left alone.  Is that not how
that works?

It sure would be nice to feed in a ``not this'' signal and all
microphones would find a way to filter it out.  It seems like an
unlikely feature, though.  I wasn't holding out much hope for that
one.

> Joe
>
> --
> Joseph Mack NA3T EME(B,D), FM05lw North Carolina
> jmack (at) wm7d (dot) net - azimuthal equidistant map
> generator at http://www.wm7d.net/azproj.shtml
> Homepage http://www.austintek.com/ It's GNU/Linux!

Thanks,
tg.