When the noise travels with you , inside your head, you have tinnitus. If, on the other hand, you can literally run away from the noise , then you may be actually hearing something that's in your environment (older model wind turbines can create a hum, for instance). Some people have very sensitive hearing and really suffer from hearing noise that nobody else hears. Check out this article about a British woman plagued by a 'hum' that no one else heard. The article details her story and goes on to report that it's "estimated that between 20 and 30per cent of the population suffer from some sort of noise sensitivity and at least 10,000 people hear The Hum." What's problematic about hearing a noise that doesn't come from inside your head is that only "about a third of cases the specific cause of the noise can be identified." Don't forget to read the comments at the end of the article -- they're interesting and might well be helpful.
Tinnitus information including treatments for tinnitus as well as cures. Obtain relief from the constant ringing in your ears, and get your life back.