Research on accelerated audio playback shows listeners can maintain comprehension at speeds up to 1.5x with minimal impact on recall. A 2021 study found that comprehension scores at 1.5x were statistically equivalent to 1x for familiar topics, but dropped significantly above 2x for new or complex material.

The key variable is familiarity. If you already know the subject โ€” say, a business podcast in your industry โ€” 1.75x is perfectly effective. For a new genre or academic content, 1.25x preserves nuance and tone while still saving time.

Apps like Pocket Casts, Overcast, and Apple Podcasts all support variable speed with some offering "smart speed" that removes silences automatically, adding another 10โ€“15% effective time savings on top of the playback speed multiplier.