Anon I have been experiencing ringing in my ears as well. It started suddenly for me almost 4 years ago. It is sometimes conspicuously absent, sometimes for minutes, sometimes days. Occasionally it changes pitch and pattern… for example, right now, it sounds kind of like a rapid car alarm, other times it's just a high pitched squeal.
I do not have tinnitus and, in fact, my hearing is undamaged and exceedingly sensitive.
What can you tell anons about your experience?