Sound is a mechanical wave that requires a medium, such as air, water, or solid objects, to propagate. When sound travels in a medium, it does not have a specific upward or downward direction by itself. Instead, sound waves radiate outward from their source in all directions, including horizontally, vertically, and diagonally.
The perception of sound traveling upward or downward depends on the relative positions of the source of the sound and the listener. If the source of the sound is located above the listener, the sound waves will travel downward towards the listener. Conversely, if the source is below the listener, the sound waves will travel upward.
It's important to note that in open spaces with no obstructions, sound waves tend to disperse and propagate in all directions. However, when encountering obstacles such as walls or floors, sound waves can reflect, refract, and diffract, causing changes in their direction and intensity. This can create complex patterns of sound propagation in indoor environments.