
While re-recording mixers do their fair share of technical damage control, their most important job is to ensure that the story is told effectively through the sound. They cover up any environmental noise, cross-fade between different tracks, apply reverb and other filters, and adjust varying audio levels, all in the pursuit of a seamless audio experience. Working in two phases-an initial sound mix and a final mix after the material has been shown to test audiences-re-recording mixers attempt to fix any final audio problems that may have slipped under the radar. In many ways, re-recording mixers are the final gatekeepers through which all audio must pass in the film, television, and advertising postproduction cycle. The best re-recording mixers excel in balancing audio so that it enhances the work's storytelling without distracting from it.

This task falls to the re-recording mixer, who takes previously recorded and edited audio elements-the work of production sound teams, dialogue editors, foley artists, sound effects editors, composers, music editors, and music supervisors-and layers them together, balancing the levels so that the sound tells a clear and effective story. One of the last steps before a film, television episode, or advertisement is released to the public is assembling its soundtrack, a word which, in the industry sense, refers not just to music but to every piece of synchronized audio, including dialogue and effects.
