[lisper]

Well, this is interesting. I was going to respond: I hear it even when I'm outdoors so it can't be transformers.

However, then I decided to check if my phone could hear it, so I fired up my DB Meter app. And funnily enough, there is a little spike right around 12kHz, which seems to be right around where my tone is. It's not a huge spike, but it's definitely there.

Weird.

[wizzwizz4]

Is the sound from your phone?

[lisper]

It's possible that the spike shown on my phone is some kind of artifact. I'll need to get another device with a DB Meter app to verify. But proximity to my phone doesn't affect my perception. I can hear it even when I'm outdoors without my phone with me.

[ForestCritter]

I started getting tinnitus shortly before moving from upstate NY. They were in the process of plastering the town with 5g every block or so. Since I've moved to rural MO in an area where even Verizon drops calls it is completely gone. Gotta wonder...