After some research I’ve found some people can control something called the “tensor tympani” and generate sounds described as a “roar” but being a subjective experience I am not certain this is exactly what I am doing.
I assumed tinnitus was mostly caused by damaging the little hairs that sense sound becoming damaged from loud sounds and not working anymore, which I would have done with headphone use in my teens/early 20s.
Squeeze your fist and hold it up to your ear. It's audible.
Partially covering the outer ear makes the flow of blood audible.
That's not tinnitus-related.
Hearing a crackling sound when you flex your ears is quite common. This noise typically results from the movement of small muscles around your ear, particularly the tensor tympani muscle in your middle ear. These muscles contract to dampen certain sounds, like chewing, but can also be voluntarily or involuntarily activated when you move your ears. This action can cause a vibration or movement of the eardrum, leading to the crackling sound. It's usually harmless, but if you experience pain, discomfort, or any other symptoms, it's advisable to consult a healthcare professional.
The clicking sound is the opening of the Eustachian tube. Flexing the tensor tympani sounds like a deep rumbling.
I find I can clench the muscle, but can only and occasionally relax the thing.
When I do clench, my ear response curve in the midrange, say 800Hz to a few KHz, is improved.
Have a fan handy? Try it and listen. You may hear a lot more from that fan.
It's one of those things where trying to describe it to someone who physically can't do it or doesn't know how to may make them question your judgment and/or sanity.
> "[...] relieve your ear pressure without moving anything else"
With controlling the muscles in the ear, one can do it without a nose clip. It's called BTV (or VTO sometimes in English)[2], and instead of forcing air in to open the eustachian tube, you just open it by muscles.
[1]: https://en.m.wikipedia.org/wiki/Ear_clearing [2]: https://www.freedivinginstructors.com/article/204
To me, it "feels" kind of like moving the base of my tongue sideways and tensing my bottom jaw (in the same way I would pre-yawn).
I've known how to do the basic BTV/VTO for many years, but it wasn't quite enough for me to equalize pressure while diving (without descending very slowly, I suppose). Just a few minutes with the techniques on that page has already improved my ability dramatically.
But for freediving with the air going towards the stomach and much faster descent it's still a bit tricky. One thing is if I'm not equalizing quickly enough, no amount of force I can muster will open the tubes again without actually doing a more classic pinch nose technique. Doing a classic equalize you will often "overblow" air in and can descend a bit before needing to equalize again. But with VTO you're only equalizing to a perfect balance so will need to make sure to keep equalizing to not get under pressure. But of course not as much hassle hands free, I try to just do click-click-click continuously, almost every kick down to remind myself to keep it open. But yeah, if I get too much under-pressure I'm not able to open it again hands free.
I also feel head angle matters a lot, so trying to not bend the neck too much to look down, but instead swim down while looking "straight ahead" instead of where you're actually going helps for me.
There is, however, a simple trick anyone can do to equalize the pressure both ways: swallow. Works wonders with babies and toddlers.
Of course, one might not be able to distinguish what muscles one is contracting, so it might be that most people actually tense both the tvp and the tympani at the same time, getting both the roaring sound from the tympani and the clicking sound from the tvp when the tubes open. Hence it's two different, but connected, things.
tensor tympani rumble = deep continuous rumbling sound you may hear when yawning
Eustachian tube clicking = a single slightly wet click you hear when you move your soft palate to block off your nasal cavity from your throat (via the tensor veli palatini muscle)
So with this I can play a melody with the ringing noise. Sometimes I do this until I fall asleep. :-)