Testing has shown that humans can't hear phase differences, unlike radio demodulators, so there's no real use for giving a sound card complex numbers. (Before

Testing has shown that humans can't hear phase differences, unlike radio demodulators, so there's no real use for giving a sound card complex numbers. (Before someone replies about snare drums, 3:1 rule, etc. — of course if there are phase differences in the audio before you mix it, it will cause audible artifacts in the mixing process. Which is why there's an effect called a "phaser".)