I can't give you a 100% answer since I'm no ATCO myself, but if you listen to around where I live it usually sounds like this:
"cleared for visual approach runway 01, maintain 2000 feet until established on final approach track".
I don't belive I've ever heard some other version anyhow, but then visual approaches aren't wery common around where I live due to noise abatment (which is also as I understand it why the "maintain 2000 feet" restriction is there).
But from my perspective, I would expect "cleared visual approach" to mean that the pilot is allowed to descend unless a restriction is given above. But then again, I'm no ATCO or pilot (I'm just one of the people giving the ATC selection process a try).