Can sound be a character?

In a theatre play or a movie, sound is used to describe situations or surroundings, and to create emotions in the audience. But in what sense can sound act as an independent character in the play?

A fictional character can be described as "the person or conscious entity we imagine to exist within the world of a work of fiction" (Wikipedia). Characters can be real people within the fiction world, but they can also be used as impersonations of something abstract, like an emotion. But what if we go the other way around; if sound, say a piece of music, is used to generate an emotion at different stages of a play, could that piece of music be thought of as a character in the play? Could sound alone constitute a role?