Get System Volume iOS

Swift 3.1

let audioSession = AVAudioSession.sharedInstance()
var volume: Float?
do {
    try audioSession.setActive(true)
    volume = audioSession.outputVolume
} catch {
    print("Error Setting Up Audio Session")
}

audioSession.setActive(true) - important

Update for Swift

let vol = AVAudioSession.sharedInstance().outputVolume

The audio session can provide output volume (iOS >= 6.0).

float vol = [[AVAudioSession sharedInstance] outputVolume];
NSLog(@"output volume: %1.2f dB", 20.f*log10f(vol+FLT_MIN));

Try this:

MPMusicPlayerController *iPod = [MPMusicPlayerController iPodMusicPlayer];
float volumeLevel = iPod.volume;

You need to import the MediaPlayer framework.