Why is Jon's voice getting weaker?

I agree. I think Jon still sounds incredible on studio recordings, including Bounce. It's live where he has problems and that's why he prefers to take the lower notes when performing live. My point was, he used to be able to hit every note live too, and not that long ago. Back in 1995 he could do it. I only noticed this starting around the time "Destination Anywhere" came out.

Is anybody here a singer.
Me and my buddies covered livin on a prayer at a talent show last may and I was so worried about those notes.I made us rehearse for a full month before the talent show.When it was time for the show I was able to make the last 'Livin on a prayer!' of the chorus but I skipped the
'whoa ooh!!' before that.
well the point is that song is freaking hard to sing.

Jon obviously prefers singing with a gravely voice. Especially on the ballads. As he's gotten older it's become easier for him to sing that way. He's been influenced a great deal by singers like Tom Waits and Bob Dylan....probably too much. He can sing much smoother and softer and higher when he wants to. At least that's what I think.

Yeah, I am a singer too. Living On A Prayer is hard, I definately agree, even for a girl, the key changed chorus can be hard to belt out. And he didn't use a falsetto on it back in the day either. That man had a range!