Resonance Audio is used to simulate 3D audio. Your ears and head act as deflectors of sounds coming in. Depending on where sound comes from, your head distorts it differently (that's how we understand sound directionality with our stereo ears!). Resonance Sound simulates the distorsión of sound in Unity, making it much more immersive and realistic.
About the knife, it took some playtesting to realized that some people wouldn't wait till the knife finished its animation😅, so I'm happy I fix the error that created on time.
Glad you liked it!