The Strip Silence effect isn't as exciting as it might sound;). But it is very useful. It is a tool in Pro Tools that removes any audio that might be present in a track during the "in-between" times when whatever is on that track is actually not playing, speaking, etc.
For example, if there is some background noise in the electric guitar track - say some amplifier hum - then that hum will probably still be audible even during the times in the song when the guitar is not playing.
Ideally, those times should be silent, but we all know that our old enemy - noise - is always lurking. Well it doesn't make any sense to have that noise cluttering up the rest of the mix during the parts when the guitar track isn't needed. So wouldn't it be great to be able to automatically zero out (make completely silent) the areas when the audio isn't playing anyway?
That's where Strip Silence comes in. You give it some settings, like a threshold above which is valid audio and below which is noise, and everything below that threshold gets silenced. I know, I know, you're wondering what the difference is between noise gating and Strip Silence.
Well, they both do that same basic job. But Strip silence has some options that a gate doesn't, such as the ability to preview - actually see - the segments that will be silenced and the start and stop points for the actual valid audio segments.
You can do something similar in Reaper with the Auto Trim/Split tool (learn that and many other recording and editing tips in our new course The Newbies Guide to Audio Recording Awesomeness 2: Pro Recording With Reaper).
Here is a video from WinkSound that shows you how to use the Strip Silence tool in Pro Tools: