Which device is primarily used to handle sound in film production?

The sound mixer is essential in film production as it is specifically designed to handle and manipulate audio elements within a project. This device allows sound engineers and audio professionals to combine, adjust, and balance multiple audio tracks, such as dialogue, sound effects, and music, ensuring that they are layered appropriately for the final mix. The sound mixer is critical in creating a cohesive audio landscape that enhances the viewing experience.

In contrast, a video codec is a technology used for encoding or decoding video files, which pertains to visual elements rather than sound. The camera is primarily responsible for capturing visual footage, and while projectors are crucial for displaying the finished product, they do not play a role in the handling or processing of sound during production. Thus, the sound mixer is the key device for managing audio in film production.