I was working on a lesson about converting energy from one form to another for my physics class, and I started to wonder, with the loose analogy between photons and phonons, what sorts of phenomena do they have in common. In particular, I know there is a sonic version of the photoelectric effect. Could there also be a sonic version of either fluorescence or phosphorescence? The closest I can imagine is a string instrument that is vibrated by a sound at its fundamental frequency. It would re-emit both the fundamental, but also sound at all the harmonics that it normally plays. But that's not very close, and I started to wonder if there was anything that was a bit closer to these.