1) Interference patterns can occur for both sound waves and light waves when the conditions of coherence and monochromaticity are met. 2) Young's double slit experiment demonstrated interference of light waves by producing alternating bright and dark bands on a screen, with the spacing of the bands determined by the wavelength of light and geometry of the setup. 3) All waves, including sound waves and light waves, can exhibit constructive and destructive interference depending on the relative phases of the waves.

1. interference

4. Sound waves