I thought I would provide some technical insight into the various VON problems and some minor suggestions on how to fix things.

PROBLEM 1.

Teamspeak 2 is far more bandwidth efficient and provides better audio clarity.

The reason TS works so efficiently is because:

1) It is single cast.
2) It uses a capped codec.
3) It uses an efficient codec.

So what does that mean?

When you sit in a TS channel the maximum bandwidth that channel will consume is set to the codec value, because you can only hear one omni directional audio stream the server only has to provide that finite bandwidth at any given time. So for instance let’s say TG gives uses the best audio codec available on teamspeak, they know the bandwidth for any given moment in time is 25.9kb. In ARMA 2 this figure can be anything from 3kb to (guestimate) 150+kb.

So what does it really mean?

It means in a nutshell that direct channel is a nightmare, it allows the players to mistakenly or even maliciously flood the network with data, I propose that if 20 players stood within a 20 foot radius and began to talk in game with direct comms the server will choke. Put simply the VON solution used in game does not scale.

In TS2 you know that even if everyone talks at once the server only has to honour the 25kb upload, in ARMA 2 it’s a data free for all AT THE COST OF IN GAME NETCODE, i.e. if everyone is using comms it effects things like flying, shooting, moving whereas in TS2 the load is on a "separate" server with a known data value.

So?

Try to dissuade players from using the lower level communication systems such as direct communication.
OR
Dont use VOP / Wait for VOP to mature.
OR
Go back to the developers and ask them to disclose any QOS work that can be done with the servers routing.

PROBLEM 2.

The ARMA 2 audio engine is immature and effected by 3rd party applications.

I suspect that ARMA2 works best with a set of standard stereo headphones; this is because users with hardware audio engines provided by for instance Creative Labs or Asus are suffering even more audio damping because of hardware effects such as doppler magnification, this is supposed to give a sense of space but is in fact just making audio totally distorted.

Efficiently users who invested in decent audio equipment are experiencing the worse VON behaviour because effects such as EQX and SmartVOL (which cannot always be disabled) are causing some sounds the engine produces to be inaudible including other people talking, this in turn makes players feel frustrated because they dont understand why someone is ignoring them.