Sorry to double post in your thread, but I GUARANTEE he heard you while he was in a coma. 100% dude. My grandma was in a coma once and we talked to her, and evnetually she was lucky enough to come out of it. She remembered almost everything we told her. So know your words were with him when he passed man. I know he was happy to have you by his side. He may not have been able to show it, but he was.