I don't think he has gay voice but he sure had a gay body. A (male) friend of mine had an affair with him. He was a major bottom with intense anger issues. He liked to beat up the guys who fucked him. Literally.
With an ass like he had, I can see many a guy pounding it hard and fast.
I still say gayvoice. Check out the lispy way he says "Long lasssting energy..." at 0:21 seconds into this video. So sexy. I can see why the rumors abound that several Hollywood men hit it back in the day.
Friend of mine had an affair with him (male friend). Said Bobby was a bottom, and he liked to beat guys up after having sex with them. Bobby had a totally tortured catholic upbringing, had as much sex with women as possible, had lots and lots of kids, got into bar fights all the time, but no matter how macho he tried to be, he just could never quit the gay. So yeah, gay voice.
What I would've given to have been able to fuck him in that glorious ass of his.