In live theatre productions, a seperate technician is needed to control the level of microphones and sound effects. Often, if the necessary sounds are simple and easily found, this technician can be trusted with the job. There are times, though, when skilled designers are required to work with a variety of sounds to help the audience establish setting, weather, even mood. These designers are known as Sound Designers.
Sound designers digitally manipulate soundbytes to create soundscapes, be it for the whole length of the play or for a few moments in the middle. Often times soundscapes will fade in to music during singing numbers, or fade into silence as characters enter a building that takes them away from auditory atmosphere. It is a delicate and time-consuming craft and, like many other elements in live theatre, is at its best when the audience notices nothing at all.
The Sound Designer is also in charge of choosing or creating music, if necessary. Musical choices can make or break the mood of a theatre piece, so there is a lot hanging in the balance. Good Sound Designers are paid well and hired often, as a bad sound design will make the play almost unwatchable.