I have Ménière’s disease, and it involves hearing loss over the course of years and it fluctuates!! Not only that it can be accompanied by tinnitus for some people. I’m not saying it’s definitely this buttt it’s another possibility for you to investigate. On another note, I’ve heard of multiple cases where people who were having this exact problem figured out that it was a plug in device for deterring mice or other pests and they had super sensitive hearing and they could hear the device every time the neighbors plugged it in.