@mahgister After reading your article I remembered I used Fourier transforms when I was working for an acoustics company and in college doing some of the first sound raytracing programs. I had a crazy smart professor who helped me out, I still feel bad about not giving him some credit for those algorithms.
One of the first things you learn as a sound man is that microphones are stupid, meaning they do not sound the same as you hear things with your ears looking at something else, it's called cocktail effect. Our brains can filter out the sounds of many people at a party and we can focus in on one conversation across the room, AI will figure that out someday but for not there are no digital filters that can do that. it used to be that we had to be so careful about one frequency covering another now there are programs that can lift frequencies that overlap other like frequencies.