I have another voice command program called Audiomatic. It will listen for a specific command (user creatable) and then give an acknowledgement sound that it's listening and ready for the next command. Goes back into the standby state after performing the given command. Works really well.Wake Command Option
This allows you to wake up DFXVoice and listen for commands. This was something that was added but at the current time, not really happy with its workings.
You can find it here if you'd like to check it out. Might give you some ideas.
And I still really like the idea of being able to use a bluetooth headset's call/answer button to activate listening. Just can't seem to find anything that'll do it!