If it was a wheel bearing, you would notice it more as a rumble at speed. You may have something as trivial as a brake pad touching the disc. This could cause a harmonic sing or a low volume squeal at low speeds.
You could do it yourself if you had access to a press in about an hour. The same time I would expect from a garage. I need one for my G60, but I am going to replace both as I am still waiting for my compessor. Will take me a couple of hours.
But for the purest engine experience, displacement has no replacement. All other methods are simply attempts to artificially recreate the benefits of displacement.
Best thing is to get a mechanic to look at it, he will be able to tell you what is wrong and correct it.Anything brake/bearing related I take my car to the garage, anything else I'll give it a bash.