* over.mp3
`329678__manuts__sound-logo-trademark-12.wav`
CC-BY 3.0
http://www.freesound.org/people/manuts/sounds/329678/

* invalid.mp3
`245764__unclesigmund__small-stones.wav`
CC0 1.0
http://www.freesound.org/people/UncleSigmund/sounds/245764/

* match.mp3
`click-high.mp3`
BSD License
https://github.com/scottschiller/SoundManager2/tree/master/demo/_mp3

* select.mp3
`click-low.mp3`
BSD License
https://github.com/scottschiller/SoundManager2/tree/master/demo/_mp3