There are certain times when you might not want the person on the other end of the phone to know it’s you calling. All stalkerish thoughts aside. Let’s say you want to call in sick and convince the boss that you’re REALLY ill. You could use this to change your voice to one of 3 high tones (female), 3 low tones (low) one original and one robot-like. Maybe you want to call into a radio show without people being able to identify your voice. Sure it’s a little odd to have someone calling in with a voice disguised as a robot, but on some radio shows that might actually be the norm! See, there’s two good uses right there! There’s also a cheaper version ($19) that doesn’t include the battery.