For the past few months, my left ear has been getting very muffled and I hear ringing all the time! It seems to go away and come back whenever it feels like it! Usually its like a weekly thing, but it's annoying! I always have to ask someone who is RIGHT NEXT TO ME to raise their voice a bit so I can hear due to this.
I have a very hard time concentrating because of this annoyance. It goes away (sometimes) for about a week, then comes back for about another week. Lately it has been getting very often though.
Yes, ringing in the ears = Tinnitus. It's normal to come and go if you have it, try to identify triggers such as caffeine, alcohol, etc and avoid those things. I've had it for 10 years after being a drummer. Good luck!