You can't do this with Gamestudios default set of functions. But you could write your own plugin in e.g. C++ from which you have access to functions for recording.
You can also use my ANet plugin, which has some ready to use voice chat functions (see link in my signature).
ANet - A stable and secure network plugin with multi-zone, unlimited players, voip, server-list features,... (for A7/A8)!
get free version
