I hear they know what causes that now... congratulations.
My wife and I figured out what causes that after 5.
She was deaf in one ear. We would go to bed at night and I'd say "You wanna go to sleep...or...what?" She'd always say "What"
Thought I was a lucky guy, she just couldn't hear!
Congrats, my 5 are grown, in fact our eldest girl is having our first grandaughter in March....
Enjoy, they grow up fast.
Terry