A common myth perpetrated by Hollywood and gun forums. Also somewhat wishful thinking on the part of the person who's racking the slide. "Once the bad guys hear me racking the slide on my Model 12-Ithaca 37-Generic Mossberg, they'll hightail it out the door and I can go back to bed!"

What it actually accomplishes in a dark house at 0300 is to give away your position to any intruder(s).