Android: Getting Notified when Audio is Played

Is it possible to be notified in Android when the Audio system starts playing audio? it looks like 开发者_开发知识库i should wire up a BroadcastReceiver, but it's not clear what i would listen for. I could listen for the MediaPlayer intent, but that would only capture when that particular application was playing audio, not when a third party application played audio, etc.

Any ideas?

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Looks like it's only available on android OS 2.2+ (froyo) via the AudioManager.OnAudioFocusChangeListener.

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Can you hook into this listener events, for pre 2.2

requestAudioFocus() and abandonAudioFocus()