If asked what a sound looks like, some people immediately imagine a waveform. This however is really a graphical representation of the compression and ratification of the air as the sound passes by a microphone. It is not really what the sound looks like in space if we could see it. I've seen people use something called cymatics to visualize sounds. It is super cool (see the video below) and can map out where the nodes and antinodes of a sound are with vibrating particles. The thing is that it is fairly static. It doesn't show sound propagating through the air.
However, the video below shows what sounds really looks like. It uses a technique called Schlieren flow visualization to make minute changes in the density of the air visible. By capturing minute changes in the density of the air and making them visible to your eye, we can actually see sound waves propagating. Very cool!
Of course, the really cool version of this would be in 3D so that you could see sounds propagate out in all directions and bounce off of objects in the room.... Maybe some day.