I saw youtube videos that claimed to do this, although I'm quite certain the videos just excluded sound and lied.
However, I am wondering if the physics of this is actually possible - to create a completely negative sound wave that cancels the sound out to a flat line i.e. complete silence.
p.s. I am not referring to white noise, which prevents the sound from being heard by overriding it with a different sound (white noise). Rather, I am referring to making a sound be completely silent by generating the inverse, opposite, or "negative" sound wave.