Usually you will recognize it as your own voice or as the feminine
and may come from internally from the area of the chest
this directs you to look inside to your own inner guidance. I do not feel it matters that you put a label on "who" it is. The Lord/Angel/ Spirit Guide /Whomever it is an aspect of you that is connecting.
This happens to me often with my own voice so I have been able to immediately observe and I have noticed even though the voice resonates withing my vocal cords do not seem to move.
If the voice is that of another or masculine it may come from a seemingly external source
and is directing you to externalities.
On 9-11-01 early early morning I awoke to my own name being called. I awoke and closed my eyes again. Then I heard my name again and my big toe was seemingly pulled. I looked to see who was there and closed eyes again. Finally I heard my name come from the corner of bedroom near ceiling and my big toe was pulled hard. I arose from bed and prayed for hours before falling asleep around 7:00 am.. //www.curezone.org/forums/fm.asp?i=503147
I awoke last week to my friends voice, her voice simply called my name as though she wanted my attention. It was as if she were beside me and when I sat up I could still feel the voice resonating. Tears came from my eyes. I went back to sleep after a while and had a dream where she said. " A put your hand on my neck my blood Sugar is high" several hours later I was in Yoga class in relaxation and I heard her call my name again and tears came from my eyes. When I left class and was driving home I heard her call me one last time so I turned around to stop by as I pulled up I received a phone message sent an hour earlier asking me to come by. When I got in she had been on the floor red and sweaty her blood Sugar had been very hiigh and then dipped to the point where she was almost incoherent , so I gave her some glucose, sent her energy, fed her and sat with her.
so where the voice comes from there you must look for guidance.