Sound travels through the air as

The motion of constant pressure lines of wavefronts that move with time is one way to represent sound propagation. Another option is to hypothetically mark a point on a wavefront and track that point's trajectory over time. The latter method is known as ray-tracing, and it clearly depicts how sound is refracted.

As a longitudinal wave, sound travels through the air. The properties of the air, not the frequency or amplitude of the sound, determine the speed of sound. 

The following basic wave phenomena can be used to describe sound waves, as well as most other types of waves.