I'm discovering that it must have been ME who was doing all the talking. In fact I've known it for a long time.
Apparently I was in the habit of "thinking out loud", a concept he never mastered or totally understood. I'm smiling because a few years ago as I spouted my every stream of consciousness, he asked me to let him know when he was supposed to reply. I told him he should just grunt or something to let me know he was listening.
For the first few days and weeks after his death, I continued my monologue.
I realized as I went to the grocery today that I am still talking to the person pulling out of the spot really slowwwwlllyy, but I am no longer giving my thoughts voice.
It's really quiet around here.
It is the sound of silence.