No, currently it's image files, TTL signals and tones. Sound files would be a nice addition though. You mentioned independent volume control though--I wonder if this might help:
http://www.empirisoft.com/medialab/h...s_features.htm
See the section there called "Adjusting Speaker Volume Automatically During Session".
Or, if you want to get way too fancy, you could send TTL signals to another program or machine which could in turn play audio files when signaled. That is beyond the scope of our help though.
See also:
http://www.empirisoft.com/Support/showthread.php?t=375