title: Difference between STREAM_VOICE_CALL and STREAM_RING
body: <p>I'm currently trying to modify the volume-settings of a phone. So, I came up to the methods I need, but now I'm not understanding the difference between <code>STREAM_VOICE_CALL</code> and <code>STREAM_RING</code>.</p>
  
  <p>It's clear what <code>STREAM_VOICE_CALL</code> is for, but shouldn't <code>STREAM_RING</code> be totally useless then? Or is it a "ring" which rings when a new message arrived, or if you're just browsing your ringtones?</p>