Can I film the police with no reason?

[KneeOn]

'composed of frequencies within the range of hearing' - is the important part. Without hearing, the sound does not exist. The tree falls, it makes all the oscillations / vibrations to create sound, they are all present, but they are not sound unless they are perceived.

Conceptually, based on our reality, then yes of course it makes a sound because we can hear, and we know that the creation of the sound waves can and would be heard, or could be recorded on equipment, however step outside what we are able to perceive, and all that tree is doing is making a load of vibrations through air and matter.

Within the range, out of the range. It doens't matter if some one is there to varify it, it just has to be within a certain band of frequency to be able to be heard. Sound is sound if it is hearable. Not if it is heard.

 

[KneeOn]

WE define what is and isn't sound based on the biologically testable capabilities of our ears and associated parts of the brain. Dogs hear things we can't. Does that mean it isn't a sound?