This is an offline captioning term, referring to the person who takes the transcript and turns it into captions. This person does the bulk of the captioning work. They do the timing, placement, and research for the closed captions, using a professional captioning software.
The person who creates a written representation of a program's audio to be used for captioning. Transcribers can work remotely and e-mail the caption editor their final transcripts or they can work in-house for the captioning company.
Live captioners are typically trained as CPRs and use that training to become live captioners. Live captioners require years of experience to be able to accurately caption in real-time.
Proofer/Quality Checker
This is a seasoned caption editor or manager who reviews the post-production captioning projects to ensure proper style and accuracy.