Though the word "dictator" has largely changed meaning in modern times, it was once common to refer to one who reads from a manuscript before a crowd as a "dictator".
To mass-copy manuscripts, a dictator would read from an exemplar before a large group of scribes. Those scribes would then write down the text being spoken.
This method can introduce textual variants if the dictator doesn't speak clearly or if the scribes mishear what is spoken, so a later editor or editors would need to go back over the manuscripts to check them for errors.
Originally, this method of transcription was used for classical literature and not for New Testament manuscripts, but it was common later in the 2nd century AD. It may be more common to see this in the university setting, such as Alexandra, Egypt (where many later New Testament manuscripts were produced).
It is important to note that professional scribes would almost always speak aloud when transcribing for themselves. This was a force of habit, as the spoken word was the primary method of communication in the ancient world, when manuscript production was much more costly than the modern era of the printing press and on-demand home printing.
By @HullBreach
