I hate to revive old dead threads, but this is most certainly me.
When I was "improving" in tinnitus sounds, I noticed yawning did not do anything. I heard no loud TWANG and nothing got louder, just my normal eardrum flutter which always happened with yawning before (not concerning).
Now that I was exposed to loud noise and pressure changes, the yawn issue has come right back, and leaves behind new sounds. It is also EPICally louder than when it started months ago.
I also woke up one morning and my left ear had lost hearing, though it was only for 30 minutes. I thought it was a pressure thing, and it worked itself out.
This all began shortly after I started Hyperbaric Oxygen Therapy that I noticed these new "fun" things when yawning (as well as that deafness in the morning).