I don't know if anyone else here suffers from this, but I've noticed lately that I'm hearing a continuous high pitched squealing noise in my ears. I don't know if it comes and goes, or I just notice it some times and not others. Can anyone tell me if this is caused by listening to lound music?
I'd agree. It does sound like tinnitis, in which case you should probably speak to your doctor.
As another possibility, if you don't listen to loud music or headphones and the tinnitis medical test comes back clear, did you buy any new electronics recently? I could hear a high pitched whine, and thought I was going mad, but it was the power adaptor in my new speakers which was making it. (See Why do Power Adaptors whine?)