The world's famous sound that adults can't hear is now available on iPhone !

The Crazy Sound is a mix of several Ultrasonic Sounds too high pitched for most adults to hear : after 24 years old, you (normally - try it !!) loose the ability to hear high frequencies.

This is why 95 % of people older than 24 will not hear the Crazy Sound !!

Have a lot of fun playing with the Crazy Sound (teachers won't hear it !!! ), now available for iPhone on the App Store !!!!