Thanks. I also suspect some sort of undiagnosed allergy/inflammation, although I do not feel at all congested. I don't have any symptoms distinct from what I've had over the past 5 years, and it doesn't seem like I'm doing anything differently. I moved to PNW a year ago, and I've started diving 10 times more than ever before, but I had no problems whatsoever last winter. No flu, cold, or diagnosed allergy in ears, nose, or sinuses within the past year.
Learning all the alternative techniques sounds like a good idea, maybe expanding my repertoire will make things easier. I equalize continuously, but that's limited by the rate, at which I manage to swallow. I can only equalize when I blow and swallow simultaneously, it's hard for me to do that fast (sometimes my throat is dry and there's nothing to swallow). At some point, I used to be able to equalize just by swallowing alone without even trying to deliberately develop that ability, but that's just randomly come and gone.
I've probably been impatient and pushed a bit too fast after experiencing the first problems, maybe that just exacerbated whatever problem I initially had and made it semi-permanent.
What's confusing is that the problem does not seem to be in an obvious way related to relative pressure changes. First 10-20 feet are generally fine. I go slow and try to maintain positive pressure. At some point, maybe 30 feet, it appears that no matter how slow I go, the ear just becomes basically unresponsive. Not always, but often. I don't go as far as pain, and do back off upon feeling any pressure. Ascending 10 feet doesn't immediately help. Even if it does, as soon as I descent another 2 feet, the left ear is just as unresponsive as it was.
Things tend to resolve eventually usually within minutes, comfort returns, but continued descent does not seem to become any easier after that with time or depth, so descent is slow. I think I can always maintain a b it of positive pressure in the right ear, whereas the left ear just barely catches up, so I can't really stay much ahead of pressure changes.
Sounds in the left ear also differ from the right one. Right is just gentle puffs, even if I occasionally push it too far and have to back off. Left, when it get stuck and later unblocks, is usually a slurping, siphon-like sound, varying from high-to-low pitch, that lasts for about a second or two. Probably there's plenty of accumulated mucus in it. Sometimes, when blocked and trying to equalize, I hear a split second high-pitch chirping sound that I can only compare to a glitch in digital audio playback, if that makes sense.
Thanks a lot, again, for your comments. I'm going to take a break from diving until this is cleared, but will definitely apply all the good advice on the next dive. Maybe I should dive with you again, it seems like I could learn a trick or two