Greetings Satanfollower, from my experience it all depends on how deep of a trance you are in...there are different levels of trance. In a DEEP trance, you shouldn't be aware of the world (physical) around you. When coming out of a deep trance, I'm often surprised to see one of my cats purring next to me, as I have no recolection of them getting close.
I'm still pretty new though, so I could be wrong.