As it happens... we have a detailed account of the work habits of one of antiquity's more prolific scholars, the Elder Pliny. In a well-known letter (3.5), the Younger Pliny describes the solution to his uncle's (evidently unusual) desire for reading efficiency: he had a lector read to him over meals and scolded a friend who made the lector slow down to repeat a mispronounced word (11-12); when taken a bath he had a book read to him or dictated notes (14); he traveled with a secretary, who performed the same duties in any spare moments (15); to allow similar accommodation during the journey itself, he always used a litter in preference to walking (16).
William A. Johnson (2010)
An instance of the ancient audio book? I wonder if this would improve my efficiency. You can read the letter in full in English (scroll down to 3.5), rather archaic English or in Latin.
