"In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid."

Sound is the RESULT of vibrations that propagate as an acoustic wave through a transmission medium such as a gas, liquid, or solid making contact with your eardrum between 40 and 40,000 hz. Again, if the frequencies are below or above that range, there is no sound.

How can there be sound if no one can hear it? That's paradoxical and defies logic. Using a general term to describe both vibrations that can and can't be experienced by a human ear is imprecise. You can call puffs of air that can't be heard by a human ear "sound" all day long, it's wrong. There is obviously no sound because you can't describe what you can't hear. You can't describe the intervals, the notes, the tones, the timber, etc.

I'm not arguing the narrow and imprecise physics definition of sound. It's not a debate.