Fainting goats usually aren't quite as vocal as other goats, I don't think. My neighbors have a whole herd of them and except during feeding time, you'd never know they were around.
They are very friendly, and not at all aggressive. When my daughter was little, she would go to the fence and feed them grass or whatever, and they would just seem thrilled to see her. None of them ever offered to charge her or butt her. Even when she was in the fence with them (supervised, of course), they never seemed interested in anything but getting petted and being given treats. Now that she's older, she still loves to go outside with the goats. She says they have a calming effect on her.