Tinnitus (pronounced /tɪˈnaɪtəs/ or /ˈtɪnɪtəs/, from the Latin word tinnītus meaning "ringing") is the perception of sound within the human ear in the absence of corresponding external sound.
If you ever are in an area of absolute quiet, still your breathing and move not a muscle. After a few seconds, you will notice that the silence has a sort of "sound" of its own, a kind of empty ringing tone. This is nothing unique, everyone will hear this, given the proper setting. An informed person will tell you that your brain is trying to interpret the lack of stimuli to your hearing and so creates a bit of a filler sound. This ringing sound actually serves a more arcane purpose, covering up a noise we are not meant to hear. This noise is not impossible to hear, and if you are persistent you can effectively "break" the cover-up sound. The next time you are silent and hear the ringing, shout at the top of your lungs for about half a minute, then be abruptly silent.
It will be different for everyone. Some will hear nothing different for dozens of tries. Others might pick up soft murmuring. A special few auditory heroes might clearly make it out on the first attempt. What you will hear is a voice that relays an account of events about to happen in the immediate future. It's like a sportscaster relaying the events occurring 10 seconds into the future. As time goes on, you will be able to make out this voice under increasingly noisy circumstances, to the point that it can be heard at any time by just concentrating.
Such an ability would doubtlessly be invaluable, no? You will be able react to any immediate danger, relate to people around you with greater ease. No one would ever surprise you. Now, of course, you are wondering what sort of horrible catch this ability entails. Perhaps the tone of the voice is so horrible that it will drive you mad, or maybe the voice will only predict your death over and over again. Of course, this isn't the case. Its' a normal voice and your ears receive it no matter what. It's simply a matter of noticing it. But there is a danger. For you see, where there is a voice, there is a body. And just like you will notice new sounds, so shall you notice new sights.
More importantly, you'll be noticed.