As someone who has only ever hit the “1x” button by accident, I am mystified by the people who speed-listen to podcasts and audiobooks on purpose. It’s all for the pursuit of efficiency, of course, as the Ringer notes: If you double the speed at which you listen to your favorite podcasts, then you can cram even more podcasts between your ears.
One can understand the appeal. There are so many podcasts! And yet there seems to be a limit to the human brain’s capacity to speed-listen, explains Raymond Pastore, an assistant professor of instructional technology at the University of North Carolina–Wilmington. Pastore has conducted five studies on “time-compressed speech,” through which he’s found a “huge, significant drop-off in comprehension at 50 percent compression, or 2x speed.”
The subject matter makes a difference in terms of comprehension, too:
Denser topics don’t lend well to speeding up, while more conversational chatter can be ingested just fine at a reasonable uptick in speed. He also says that familiarity with a subject can overcome higher listening speeds.
If you must speed-listen, Pastore recommends 1.25x, if you’d also like to comprehend what you’re hearing. You’re okay at 1.5x, too, but anything faster than that and “you’re really starting to sacrifice learning.” But just be aware that by doing this, you’re potentially breaking your favorite podcasters’ hearts: The specter of speed-listening, Invisibilia’s Alix Spiegel said, will likely have the unhappy side effect of “crush[ing] the dreams of idealistic radio producers twice as fast.”