Sound is made audible air vibrating air molecules. Sound is a form of energy, we can’t see it, and we can only hear it when the volume is high enough and if it exists between 20Hz and 20kHz, the audible range of the human ear.
Sound also moves through liquids though, and Eva Schindling created a computer model which simulates the collision of two sounds in a fluid environment. The resulting form is then modeled out of Styrofoam. Now we have a sound we can touch, but we can’t hear it!