KEY POINTS-

• Listening to audiobooks and podcasts at higher rates of speed has become popular.
• Research shows that large increases in speed results in poorer comprehension.
• For most people, small increases in playback speed are best.

When children first learn to read, they move their eyes haltingly along lines of text as they try to figure out the words they encounter. Through years of practice, however, most people become highly skilled at this activity, with corresponding increases in reading speed.

The typical adult can read and comprehend about 280 words per minute (WPM). Since the normal speaking rate for English is 150 to 190 WPM, this suggests we should be able to understand spoken language at rates that are higher than those we encounter in daily life.

This raises an intriguing possibility. Even though speed reading is more hype than anything else, perhaps speed listening is possible. Imagine being able to power through audiobooks or podcasts at rates that are much faster than normal. It would almost be like having a superpower. But is this really possible? And if so, is there an upper limit for comprehending spoken language?

Speeding Up the Spoken Word

Audiobooks are typically recorded at the low end of the normal speaking rate—about 150 to 160 WPM—for maximum intelligibility. But smartphone apps allow the playback rate of recordings to be increased, and some people choose to listen to content at speeds of 1.5 times or even 2 times faster than normal.

There are many online testimonials about the benefits of speed listening: it’s often touted as a life hack that magically creates more time for consuming spoken content.

But what does the science say? Researchers have manipulated speaking rates in controlled experiments to assess how this affects comprehension. These studies show that speech rates can be increased by about 25 percent without too much impact on the participants’ understanding. But when the rate of speeded-up language approaches 50 percent, there is typically a significant drop in comprehension.

Speed Versus Comprehension

This shouldn’t come as a surprise: We encounter such tradeoffs in many aspects of daily life. If we are in a hurry at the supermarket, for example, we almost invariably arrive home without some important item that we intended to purchase. A quick calculation is likely to be inaccurate. And the drop in comprehension for extremely rapid speech suggests there is an upper limit in our ability to process language.

As I describe in my book on miscommunication, there are many reasons why we misunderstand one another, and one cause is our inability to make sense of speech that is too rapid.

Listening Versus Reading

Listening to speech differs from reading in many respects. Spoken language is evanescent—once we’ve heard something, it’s gone forever. On the other hand, when we read, we can easily jump to a previous line of text to verify something, like the name of a character in a story.

When we listen to an audiobook or a podcast, we do have the ability to stop and jump backwards in 15- or 30-second chunks. This is increasingly necessary at high speech rates, and it can be quite tedious to back up over and over again. When we read, however, it’s easy to flick our eyes upward on the page to verify some previously encountered detail.

And just as with reading, people listen for different purposes. If your goal is to expose yourself to as many new ideas as efficiently as possible, then increasing the playback speed of a podcast makes sense. This can take some getting used to, although most people adapt quickly.

But if your primary goal is to relax with a good book, you might find faster speech to be fatiguing and less enjoyable than listening to a normal speaking rate.

The Goldilocks Zone

For each person, there is probably some sweet spot with regard to listening speed: one that is not too slow and not too fast, but just right. A study conducted by Raymond Pastore allowed participants to adjust their playback speeds to a comfortable rate, and he found that this Goldilocks zone is about 10 percent faster than the usual recorded speaking rate, or about 165 WPM.

The next time you decide to spend some time with a podcast or an audiobook, feel free to adjust the playback speed. Don’t hesitate to experiment until you find the speech rate that’s right for you. And it’s important to be flexible: a murder mystery in which every detail is important may require a slower speed than a simple summary of the day’s news.

You may not develop a new superpower—but you probably will save a few minutes of your time.