I have to say that I think if a tree falls in the forest and nobody is around to hear it, it still makes a sound. I think this riddle / philosophical conundrum is solved.
Why? Sound is air being disturbed. The air is still disturbed regardless of if anyone heard the effect.



It’s air being disturbed. Microphones have no brain. Deaf people can still feel bass vibrations caused by speakers disturbing the air. It’s a fully physical phenomenon that happens regardless of there being an observer.