Most of the time the average person won't here the squeeking of pads( Music ,windows always up,road noise).
So with that said you should always and not just for brakes .Find a quite parking lot once a week if possible on your travels and do some figure 8's with the windows down at low speeds this will let you hear a lot of things.
And remember pads are cheap, rotors and shafts are not.If your pads wear down enough they will cause the rotors to waer and even the shafts as they will be jerky not smooth when stopping.