how to...lan language laboratory

Hi folks,

I would like to realise a "multimedia language laboratory" for a friend of
mine if it will be possible without a total rewrite of the software.
I tested two professional windows-solutions and wasn't satisfied at all with
the software itself and expecially the price.

Simplest classroom situation:
Every student and the teacher has it's own PC in a lan.
Every PC is equipped with soundcard, quality-headphones and -microphone.
Every Desktop uses KDE in Kiosk-mode.

The simplest solution should be:
- The teacher should be able to open a channel to either one, some or all
students to talk to them.
- The teacher should be able to also do the same with the incoming listening
channels.

To shorten all that:
The teacher should be able to have a kind of network-sound-mixer where
he/she can controll sound- input,output and direction.
If this mixerfunctions would be available via commandline, this would be
very nice and easy to implement in cgi scripts for the GUIs. If only
available via a shared library, I would implement them into a apache
module.

I'm not very familiar with the different sound architectures (OSS, ALSA) and
soundservers and Mixers, so I need a little help by more experienced users
with this topic.

Now to some questiones:

- If you have any idea how this could be realised very easy, pleas drop me a
line, please also tell me about programs which could help to realise this
;-)

- How do I redirect sound from the microphone directly over the network to
another computer, which also takes this eg. as line5 in? How could I send
the sound directly to all computers in the network? Do I need to have a
client/server proggy to open a socket or is it possible to create something
like a named pipe to every other client?

- I read a few things about Arts and know I can enable network-transparency.
I also took a few looks at Arts-Builder and Arts-Control, but must say, I
really don't understand Arts and how it works, but I saw you should be able
to do really nice things with those two proggies.
If someone could tell me if Arts could do the trick, please point me into
the right direction where to start creating the Mixer.

- I also read about sound-proxys, which are able to redirect the sound to a
different box. Could this probably be a helper?

- What about using open-video-server or similar software in this context?

- Are there some projects out there which deal with this kind of problems
and solutions?

If you have any other Idea which could help me, please let me know ;-)

Many thanks in advance,
yours Henri