When I Swallow, Sometimes My Ear Cracks, Sometimes It Doesn't — Why?

I'm a bit confused about what this can be.

Sometimes my ear cracks loud, sometimes it cracks normally and sometimes I can't feel it cracking...

The cracking sound, does it originate from the ear drum or the eustachian tube?

 

This is what I found from Google.

Symptoms of Eustachian tube dysfunction

• Your ears may feel plugged or full.
• Sounds may seem muffled.
• You may feel a popping or clicking sensation (children may say their ear“tickles”).
• You may have pain in one or both ears.
• You may hear ringing in your ears (called tinnitus).

 

Maybe the bones in your ear?

 

No body knows the source of this for sure but maybe is related to the tensor timpany muscle in the middle ear and or the eustachian tube

 

Do you visit ENT ? Any answer ?

 

Yes but didn't receive any help....