I have had tinnitus since about 1986. Most of the time I don't even notice.

[Gaugamela]

2. Does this sound like what you're describing?

I used to hear this on occasion when I was in my 20s and 30s, but now I hear the tinnitus cicadas. If this is what you hear, it’s not tinnitus:

Maybe you hear it. A low frequency hum, almost a vibration, just on the threshold of human hearing. It’s not particularly loud. In fact, you might not have even noticed it yet – but once you do, you can’t stop hearing it. It sounds like a truck, idling on the street in front your house. Or the atmospheric din of an airplane flying overhead, that never gets further away. You can hear it when you’re outside, but it seems louder indoors, and particularly at night, when you’re lying in bed. Maybe it keeps you awake. Maybe it causes you headaches, dizziness, even nosebleeds.

If you do hear it, you’re among the roughly 4% of the world’s population affected by “the Hum”, a frequently reported but little understood global phenomenon.

https://www.theguardian.com/books/2021/jul/07/the-hum-mystery-noise-says-a-lot-about-modern-life