I have had it for ten years. Eventually you don't hear it until you think about it. Mine is very loud at the moment. Just another sign of aging. Nature's own memento mori.
Yes I notice if I'm distracted it seems to go away. But unfortunately this only happens if I happen to be outside, surrounded by traffic. As soon as I'm indoors (esp. at home, in the evenings) it comes back & it's hard to think about anything else.