I've always had this "buzzing" or sorta ringing like sound in my ear for a while now, sometimes when I focus on other noises the sound goes away or other times it comes back in a semi-loud pitch, I've been to an ear doctor before who said I'm fine but this buzzing sound can get annoying and trigger me into a panic attack or obsessive thought at times.
Sounds like tinnitus. Had it bad since I was a kid (lots of ear problems, tumors etc) - but most of the time i'm able to *tune out* and basically ignore it. Anxiety makes it harder to ignore. If it gets really bad, I know CBT is often effective as therapy.