TubeNet

I get a crackling when i play and others play. I have about 50% of my hearing left or less. But mine might be different. I can't be exposed to high db or my left ear will totally cut out. dunno might need to get your hearing check. But tahts whats up with me. hope this helps a little. best of luck. oh and i got a pair of earplugs to use which helps. takes a bit to get used to but it helps none the less. best of luck.

I have had a series of ear infection throughout my life, and have had tubes put in twice. And, once my ear, nose, and throat doctor said that playing the tuba helps the ears rid itself of fluids, etc. The popping feeling is actually doing good for your ears' health!

Putting a single earplug in, on the bell side, may help things. It's worth a try for $12.00.
http://www.etymotic.com/ephp/er20.aspx

As I understand the mechanism of the Eustachian Tube, it drains accumulated liquid and gel from the inner ear to drain down the throat. This is a good thing. Perhaps, when playing brass instruments you are manipulating the jaws and throat and flexing the Eustachian tube, causing it to drain. This is a good thing. Maybe there is a reason it is filling up? Might be worth looking in to that. Think of the old days, before pressurized air craft cabins were common. The airlines passed out gum so everyone could chew and thus release inner ear pressure. Same mechanism, here.

Have you checked it is not just wax in the ear? I frequently have problems with wax build up. I don't know if the sound of my tuba, or maybe the percussion which is so often situated close by causes.

A couple things:

Is it allergy season for you now? Something different in the environment you might be reacting to?

Both dairy products and soy products can cause your body to produce mucus that can clog up your ears and cause those crackling noises. I finally traced a similar ear problem down to the fact that I had been eating a lot of soy yogurt. It took two weeks to clear up after I stopped; I then re-tested (I always want "proof") by eating the soy yogurt again, and the problem came back, so I was pretty sure that was the cause.

MA

I've had ear problems for decades, and I learned about the physiology of the ear long ago. Here's what I think is happening:

Tuba players tend to play with the back of the oral cavity very open. I think that you're opening the back of your throat so much that the eustacian tubes are opening, and the act of blowing is forcing air into your middle ear. When you stop playing, the excess air is bleeding back through the eustacian tubes when you flex the back of your throat, causing noise and popping. This is irritating, but not harmful. Unless you're causing yourself pain, this is actually good for your ears.

Also, regarding the cutting out of hearing at high decibels: the stapedius muscle is in the middle ear; it contracts in response to a loud noise, making the chain of ear bones more rigid so that less sound is transmitted. This response is called the acoustic reflex, and it helps protect the delicate inner ear from sound damage. (lifted from the Web)