I'm not a doctor so all I can do is point you to places like [1] though I've had tinnitus for 30 plus years. I worked around loud equipment with inadequate ear protection - but the defining blow was having my head beside a push bike tyre when it exploded resulting in partial deafness for a day or so.

It's different for everyone, mine is actually damage to the small hearing hairs so no cure hope at all. It takes a while for the brain to adjust and slowly ignore the noise but only to a point. Different things work and you've probably been told about white noise could could help out.

For a start my tinnitus was like standing on the tarmac beside a jet screaming its engines ... making any conversation a great deal of effort trying to ignore the loud whine. It eased over the years where I could almost mistake it for a loud chorus of crickets or cicadas at night, which strangely was more easy to think that's just what it was. Mostly though lately I can ignore it or simply forget it's going on.

[1] https://hearingandme.com/can-tinnitus-be-cured-what-science-...

Music all day long diverts attention.

There's an oldies station nearby, and's it's very effective and uplifting.

Music at bedtime to mask odd country noises of unknown origin.

1) Do you hear it away from your home? If yes then it’s in your ear not your router.

2) The only solution to tinnitus is to stop fixating on it and eventually stop thinking about it completely. The only way to do that is to make sure you can never hear it. Learn how to mask yours with music or white noise. Especially while sleeping. It will eventually calm and might even go away. 3) Do not seek tinnitus support groups/subreddits online. They are fully fixated by definition and just reading their posts will make your symptoms worse.

Try moving your couch. It's possible that you're sitting in a resonant part of the room that amplifies background noise through room modes: https://en.wikipedia.org/wiki/Room_modes

That's a long shot, though.

funny enough i thought i was getting tinnitus, something that was bothering me for almost a year. turned out it was my power adapter’s coil whine