This is interesting. I've never given it much thought (and didn't know MEBT was a thing), but I've experienced the same discomfort while: SCUBA diving, skydiving, ordinary air flight descent, and even some hilly car driving.

Doc says there's nothing wrong or clogged etc about my eustachian tubes. It's easy enough to manage (except skydiving, where the pressure change is too fast and not under any meaningful control of mine!), but if pseudoephedrine would make things less distracting during SCUBA, I'm interested.

Thanks for the links!