The propagation of high frequencies sound waves is more directional (specular), and they don't diffract as much as low frequencies. Low-frequencies diffract and thus propagate in a more omni-spherical fashion. This, to my knowledge, applies to all waves, not only sound ones.
Now trying to imagine the air particles hitting one another at low/high frequencies doesn't really unlock why this happens. I am aware that deep understanding of wave theory will provide the answer.
But is there a simple, visual explanation to why this happens? And if not, is there at least some simple mathematical equation that can provide the answer?