Possible Duplicate:
get current system volume level on iPhone
I am working on an application, which includes sound. During runtime I would like to check the sound level to be able to give the user feedback by showing a pop-up with the text “the volume is too low” if the sound level is too low (just an example). I know how to check if the sound is muted or not, but how to I check the sound level?
use https://developer.apple.com/library/ios/#documentation/mediaplayer/reference/MPMusicPlayerController_ClassReference/Reference/Reference.html
This gives you a value between 0.0 and 1.0 so you can then do a check