| | Re: all vs everything
The first one - yes, possibly. Because what you heard wasn't actually the phone itself ringing, but the sound that comes over the wire to symbolise the phone ringing. So here, yes the sound of a ringing phone does contrast with a busy signal.
But in the other examples, to me it still doesn't make sense. What you are saying is that you heard a phone which was ringing - in other words you heard the sound which was coming from an actual phone. You're not trying to tell me that you heard a specific type of phone.