9.3 - Behavior of Sound

...we can measure it with a loudspeaker, convert it into electromagnetic representations of compressions and rarefactions, and see them interfereing with it ourselves.

...when two or more sound waves occupy the same space, their pressures affect one another. The waves do not bounce off of each, but they move through each other.

...the change in pressure of the particles is converted into waves so that we can see them, and they interfere because that's how our interpretation of transverse waves works.

...the pitch of two waves will always be percevied to be quiet and loud in different areas.