I think I have tinitus.
At night I can hear, in my right ear, two tones that alternate. a bit like someone trying to play a tune on a flute with only two notes. It warbles away all night, louder when I have my ear down on the pillow.
It started a couple of weeks ago, and I first thought it was some kind of alarm tone from a nearby industrial plant. However, I am pretty sure it is not, unless the same warbling tones are played near MiL's house too!
Checking on the online tone generator I think the tones are about 912hz and 1120hz.
https://www.szynalski.com/tone-generator/#9354,v1
I should look at getting a referral to an audiologist, I guess.