I am not a doctor , these are just guesses .
Tinnitus are a common symptom of EHS people.
I also suffer from it.
There are several types, I think those which are related to EHS or EMF are more of a sensitivity of the inner hear issue.
There is the high pitch noise, the law pitch noise and the supper hearing issues.
I think the higher pitch noise is caused by ELF exposure, the low pitch noise from RF exposure and the supper hearing is cause because of an inflammatory situation in the inner heat because of exposure to EMF in general.
If the tinnitus keeps me from sleeping I put some music on , or turn the fan or AC on. Other sounds makes it less noticeable. Other than that I try to be as less exposed as possible.
all the best