Ricardo Vieira

I wanted to create an application where the user spoke a determined word (e.g. KinectVoice), after this word the user would have 5 seconds to say the command. In other words, i need to create a threat that runs allways. The problem is that we will need to delete what has been said of X in X time (minutes, seconds), if not, the application gets a lot of load! Someone can tell what is the best way to accomplish this?