Sound is a part of the Force Aspect, which is made by combining Flow and Land.
This is an active fysa. Users have enhanced hearing, and are able to even translate vibrations felt from a surface into sound.
They can manipulate sounds, increasing their volume or diminishing it into silence within 10 meters (11 yards). They can create new sounds within their field of influence, creating phantom voices or tunes.
Vibrations of sound can cause tiny shock waves equal to the force of the user's physical strength.
You must have already learned either Flow or Land in order to learn this ability.