I still try to figure out what caused it. I had a bad cold and felt a back-pressure when I blew my nose, but didn't hear it right away. I actually first heard the tone in my left ear after yanking out an annoying eyebrow that was protruding straight out. I have often felt an itchy sensation in my left ear for years prior. I would create a vacuum in my ear using my finger to try toget whatever it was out. I love to smoke cigars, but when I do the tone instantly gets about twice as loud. I have also noticed a correlation to chocolate and dairy making it worse. It never goes away but is usually tolerable...barely. At times it is not. My heart goes out to you fellow sufferers, especially those who have it even worse than me.