What is another word for sound-on-film?
Pronunciation: [sˈa͡ʊndˌɒnfˈɪlm] (IPA) 
Sound-on-film is a term used to describe the method of recording sound directly onto a motion picture film. However, there are many synonyms and related terms that can be used to describe this process. For example, one could use the term "optical sound" to describe the technique of recording sound onto the filmstrip using light and photo-sensitive materials. Another synonym for sound-on-film is "variable area", which refers to the method of recording sound using varying widths of track that correspond to different audio frequencies. In addition, the term "soundtrack" can also be used to describe the audio portion of a film, whether it was recorded on film or through other means.
