To Toggle On/Off music, please follow the direction below:

NOTE: On iOS devices, if you are having having trouble hearing sound from Puzzingo. It’s possible that the slide-switch lock and been accidentally changed to a mute lock. Here is an explanation of the issue and how to address it.

http://www.tothepc.com/archives/ipad-slide-switch-lock-screen-mute-ios-4-3/
http://support.apple.com/kb/HT4085