16mm Film:
Sound film for 16mm home movies is exceptionally rare. For reels of films like commercial prints, student films, news pieces, however, audio tracks are much more common.
The soundtrack on 16mm films will always be included along the non-sprocket side of the film. So sound film will only be written on 16mm film with a single set of sprocket holes. The first step to check for sound on 16mm film then is to check the sprocket holes. If the film has sprocket holes on both side of the film, then the film does not have sound.
If you have 16mm film with a single set of sprocket holes, then you may have sound. 16mm sound comes in two formats: magnetic sound and optical sound. Here's how to check for each: