Though not completely impossible, it would require heavy client modification to be able to listen to the systems sound input, send it to the server, and receive it from the server. I suppose it would be too difficult to do it through the client
One other method is by creating a new program which can read the location of the character from the client (x,y,map) and then send it to the server, the server would then send it to the other clients that are in range of the xyz of your character.