system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: sometimes when I'm listening to music through headphones and I yawn, the pitch of the music shifts down a semitone or so for the duration of the yawn. Why does this happen?
gpt
The sinuses are connected to the inner ear via Eustachian tubes.  In a yawn, the musculature around the jaw can squeeze on these tubes, affecting the pressure in the inner ear.  This pressure change also effects the resonance of the ear drum and the anatomy in the inner ear.