Sound effects are the sounds that are created artificially to make a play more realistic, especially a radio play.
sound effect in British English
noun
any sound artificially produced, reproduced from a recording, etc, to create a theatrical effect, such as the bringing together of two halves of a hollow coconut shell to simulate a horse's gallop; used in plays, films, etc
Examples of 'sound effect' in a sentence
sound effect
Tropical sound effects make the scene changes atmospheric, and a talking parrot provides some light relief.