As the title says, this is not how bullet sounds work.

You don't just hear a whizz when a bullet flies close-by. That is a hollywood myth. You only hear the whizz sounds when the bullet is going subsonic, this is usually only the case with stray bullets which have lost all their energy and gone subsonic and with ricochets. Hearing a "whizz" sound coming out of the barrel of a dude shooting right next to me in the game is extremely immersion breaking and makes it feel like I'm playing in some ♥♥♥♥♥♥ b-movie.

Bullet sounds can be compared with a stick and a whip. When you swing the stick you hear a "swoosh" sound, this is the sound the stick makes when moving through the air. The stick is subsonic so you just hear the "swoosh" of the air going around it and that's it. This is the same as with subsonic bullets making a whizz sound.

A whip however, makes a "crack" sound because the tip of the whip is actually going supersonic. It's going faster than the sound of the air around it meaning it will pretty much compress the entire "swoosh" sound into one big sound which you hear as a "crack". This is what supersonic bullets sound like.

This video is a good example of the difference between supersonic and subsonic bullets
https://www.youtube.com/watch?v=nWQJTFeVBfg

You actually notice the whizz sound with the subsonic rounds, but the supersonic sounds are just a loud crack.