When he was little, the boy used sounds for things instead of words. Our vacuum cleaner was a 'wvooooee' (imagine it sounding like a vacuum), a drill was a 'brrrrrzzz' and so on. And it was deliberate, the sounds were all distinct and only used when referring to whatever he was talking about. It was quite cute and endearing.
Fast forward to now, when he talks non-stop, day in day out, and with a vocabulary that often surprises hubby and myself. He no longer needs the sounds to describe the items, now the sounds are an accompaniment as he's 'using' the items. If he's 'making' bread he does an almost spot-on impression of my bread maker, or if he's cutting the grass or using the weed whacker, it comes complete with lawn mower or weed whacking noises. But his most used toys at the moment are his tools. When he's doing fixing jobs around the house and using all his tools he (apparently) has a number of different drills, and they all make different noises. Often he'll classify them as 'this is my quiet drill, this is my loud drill, and this is my really loud drill'. And of course, guess which drill he uses most often - I think I should buy shares in advil!