We know that the speed of light depends on the density of the medium it is travelling through. It travels faster through less dense media and slower through more dense media.
When we produce sound, a series of rarefactions and compressions are created in the medium by the vibration of the source of sound. Compressions have high pressure and high density, while rarefactions have low pressure and low density.
If light is made to propagate through such a disturbance in the medium, does it experience refraction due to changes in the density of the medium? Why don't we observe this?