Phantom sensation, broken nerves could be one cause of tinnitus.

I've had phantom tooth pain several times from teeth that were extracted
years ago.

I know a veteran who has pain and other sensations in his fingers of his
non-existent arm after losing it over 30 years ago.

Certainly damaged or broken nerves is other areas are still partially active
on the brain pathway.

I'm not sure if there are any treatments to either deaden or numb these
remnant nerves but there must be some researchers perusing that road.

Jamffer