My wife hums when she's asleep.
This is new but it does not seem to be cause for alarm. She just hums. It's never really a song I recognize. She hums a little tune to herself and the baby.
She's been having such a difficult time sleeping so rather than wake her I just let her do it. She's always been able to sleep through anything. Not this. This is an entirely new thing.
I have passed my insomnia on to her.
However, when she does sleep... she hums.