I'm sorry but I have to disagree. All people don't have tinnitus, not even mildly. I'm sure there is some brain activity that a person can sense, especially when a person is exhausted, but our tinnitus' are due to an imbalance and are hyperactive. So there is a difference between the two. An actual physiological difference. Its not that we focus on it, and other normal people don't.
I based my comments on the Heller and Bergman study, where subjects were placed inside a sound booth for 5 mins, and were asked to make notes of sounds they detected during the silence. From these findings, the researchers concluded that tinnitus is present constantly, but is masked by ambient noise. As the study states 'these researchers concluded that all normal functioning auditory systems in humans are constantly producing a low level tinnitus that is audible only when listeners are in a sufficiently quiet environment' Subsequent studies have also substantiated this and conclude that normal hearing adults experience tinnitus in silence.