There was an earlier thread on tinnitus https://news.ycombinator.com/item?id=21572827 where people had some techniques for relief. Maybe this could be useful.
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For those with unilateral tinnitus that seems influenced by neck stretches or TMJ issues, try sleeping on your back or on the opposite side to avoid pressure on the affected ear.
Also, consider getting an MRI to check for possible causes; in my case, a vascular loop was found contacting the vestibulocochlear nerve inside the internal auditory canal.
While I consider my case largely managed, it still flares up a few times per month, usually triggered by irritation or inflammation (allergens, getting sick, poor neck posture, loud music for hours)