FD...if you get a chance to read these posts, I'm hoping you'll get to this one. He may not be able to hear you all the time, but there are times of consciousness when he can. I was with my grandfather when he was ill. I talked to him, prayed for him and read to him never knowing if he heard me. When I was getting ready to leave, I kissed him and told him I was leaving and would see him the next day. He started crying. He'd heard me. I didn't leave and he passed several hours later.
I talked to the visiting nurse about it and she said they do go in and out and do hear everything that's going on, so it was good that I did talk to him.
Richard knows you've been there and knows you love him. Take heart in that. He knows.
Blessings