“Walla” is a strangely named job for actors who provide background noises in movies and TV shows. Imagine a scene where two actors are sitting down and talking with each other. The background extras are instructed to walk around silently so the two actor’s dialogue can be heard and recorded on a clean track. Once the scene is ready for editing, it is projected on a screen in a specially designed  recording studio so the background voices can be added. The “Walla” actors watch the screen and record voices for those extras moving around in the scene. Movie magic!