"Friendly" sound that might be considered incidental or that you may want to hear bounces around corners.
Weaponized sound can bounce but the drop in energy [necessary for damage] is so substantial it becomes what you are describing.
If you don't understand, go to a rock concert. Bring a piece of paper. Hold it in front of your head, then in front of either ear (while moving your head--most significant change will be orthagonal to the direction from the speakers to your head). You will be surprised.