Maybe there is, but not for humans! If we sensed sound like we sense colour we'd only hear the amount of bass/mid/treble not the individual pitches. But if th

Maybe there is, but not for humans! If we sensed sound like we sense colour we'd only hear the amount of bass/mid/treble not the individual pitches. But if there's such a thing as a non-linear medium for light, then transmitting two wavelengths through it should do interesting things depending on the ratio of the wavelengths?