Greeting Physics Forums; my first post here. Thanks in advance for your time! Approximately how many soundwaves compose what we can say is a single noise, like a drumbeat? I know there are multiple frequencies involved and our brain interprets this in it's own way. There is interference and phasing and I read that the Fourier method(?) helps with this. Simply can you derive a single soundwave from let's say a car crash, or is it a high-order more of soundwaves like each square inch of metal on metal collision producing multiple waves and our brain (or a recording device) forming a general picture?