There isn't a single instrument that lets us "see" sound waves in the traditional sense. Sound waves are vibrations in a medium, like air, and we can't see vibrations directly.

However, there are ways to visualize the effects of sound waves, which can give us information about their properties:

* Oscilloscope: This instrument displays electrical signals as waveforms. When connected to a microphone, it can show the changing air pressure created by sound waves.

* Chladni Plates: These are flat surfaces that vibrate when a bow is drawn across them. The patterns of sand or salt that form on the plate reveal the nodes (points of no vibration) and antinodes (points of maximum vibration) of the sound waves.

* Schlieren Photography: This technique uses light refraction to visualize changes in air density, which can be caused by sound waves.

* Computer simulations: These can model the propagation of sound waves in different mediums and under various conditions.

These methods allow us to study and understand sound waves, but they don't provide a direct visual representation like seeing a light wave.