RT from end of stimulus rather than start of stimulus?

I have about 400 voice recordings, all of different durations, that I am inputing into directRT to play. For my study, I want RT to be recorded from the offset of each audio voice recording to the button press response. How do I make this happen as directRT typically records from onset of stimulus to button press response, rather from when stimulus is done playing to button press response.

Tough task. DirectRT has no way to detect the offset. You would need to read that under each file's audio properties or look at them in a wave editor like Audacity (see [URL="http://www.audacity.com"]www.audacity.com[/URL]) if you want to make a relatively precise detection of the amplitude fall off (it's always a judgment call because it's usually gradual).