i guess the only thing predictable about tinnitus is it's unpredictability. i have tinnitus as well. about 15 years now and it started (most likely) from viral infection in the inner ear. acoustic damage is just one of the ways so yours may have been viral as well. i can offer no explanation as to why your tinnitus switched ears. i can't say that i have seen this in clinical practice so this is a unique experience. remember that tinnitus is usually not a real noise by an illusion of a noise that our brain creates. i can't comment on your brain tumor concern but fortunately for all of us tumors are a very rare cause. if you are going to see a doctor see a neurotologist (an ent/neurologist).
i've had tinnitus for 12 years in my left ear. suddenly i have tinnitus in my right ear and my left ear is fine. how? . i went to doctors got hearing tests got mri's etc. the doctors said it was just inner ear damage (even though i listened to music at a low volume and had never been to a concert). after 12 years suddenly my other ear is ringing and my left ear is fine (i tested this by making soft noises on my left side that i hadn't been able to hear). i am confused about how suddenly my ears decided to trade tinnitus. does this mean i have brain tumor after all? . and yes i know i should see a doctor.