Over the years, I've heard many people sample this one sound. There is no way I can describe it other than a rhythmic pulse of an alarm. I've linked two songs that use the sample for the main part of the beat, so you'll be able to compare and figure out what it is. I've heard it on many other songs, but these two keep it around for the longest time. Where the hell did this thing come from, and why does everyone use it (besides it sounding cool)?