U know, technically, setting the audio of a cock hero video to surround sound, routing a separate "stroke meter" audio track to one of the channels (maybe the sub/center speaker channel), and then hooking up this device to only that channel could possibly work. Most PC's have a surround sound setup ...

I've actually tried using CH videos for e-stim a few times and they're actually pretty good as-is. I use an ET-312 and basically the trick is to just adjust the gain on the stim box so that it's mostly just picking up the beats. You end up getting some beats from the song that aren't on the stroke ...