Actually neither. There are very tiny bones in your ear that are held in place by muscles. Usually sound makes the bones vibrate which translates to sound. Tinnitus is where there's another reason for the vibration. In my case muscle spasms in those tiny muscles, but it still translates to sound.

I asked because when I bite or open my mouth wide, the intensity of the sound increases

Not sure, however, when I open my mouth wide the T intensified.

It's most commonly related to hearing loss or hearing damage. It is also possible to hear your muscles in your jaw when they are strained.

At least that's my experience with it.