Originally posted by Capt. Dash Riprock:

If you have a mounted head of a boss on your wall at your base respawn they will on occasion 'talk' and usually accompanied with a crying sound as well, you will see what they say in text flashing on the screen briefly, my guess that is what it was.

That makes perfect sense. We've got some Eikthyr heads mounted in our meadhall for aesthetic. Thanks my dude!