Most other aspects of audio for moving pictures occur during the post-production phase, everything is done after filming.
One major aspect of audio post-production is the use of automatic dialogue replacement (ADR).
Sometimes the original production audio lacks in performance or quality, and one or more actors work in a sound studio to record some or all of their dialogue from the project.
Reworking and enhancing voice-based media is prevalent in the form of noise reduction and volume normalization.
With many techniques being adjusted specifically for vocal audio, the field is becoming more understood as unique to music production.