From the inception of sync sound in the late 1920s to the modern day, sound in animation has assumed a variety of forms. This article proposes four principal modes that have developed in the commercial realm of American animation according to changing contingencies of convention, technology and funding. The various modes are termed syncretic, zip-crash, functional and poetic authentication. Each one is utilized to different aesthetic effect, with changing relationships to the image. The use of voice, music, sound effects and atmos are considered as well as the ways in which they are recorded, manipulated and mixed. Additionally, the ways in which conventions bleed from one period to the next are also illustrated. Collectively, these proposed categories aid in understanding the history and creative range of options available to animators beyond the visual realm.