Why is my voice significantly deeper whenever I wake up?

Question

I usually have a deep voice, but when I wake up, or when I am sick, it is really deep.

Answer 1

Your larynx (vocal cords) are relaxed and loose, which means they vibrate slower, which results in a lower sound.

When you are tenser, your larynx tightens, which makes the pitch of your voice go higher.

Pay attention when you argue with someone; their voice will go up in pitch as they get more and more stressed out.

Answer 2

Your vocal chords are in a relaxed state from the peroid of rest