You Can Literally Hear the Sound of Silence, Surprising Study Shows

Imagine sitting in a bustling cafe, with the sound of dishes, the hum of conversations, and the whistling of the espresso machine in the background. Suddenly, everything becomes calm again. Do you hear this silence?

It seems like a silly question, but according to a team of philosophers and psychologists, it’s possible. Indeed, illusions based on silence are perceived in the same way as sound illusions. This means that the brain treats silence as if it were sound.

In other words, silence is not simply the absence of sound, but something we can actively perceive. So Simon and Garfunkel were right all along!

The sound of nothingness

Whether or not silence is a perceptible property of sound has been a topic of debate for many years. This conundrum has mostly amused philosophers, but only recently has our perception of silence been tested more rigorously with the scientific method.

For their study, researchers at Johns Hopkins University used auditory illusions to demonstrate how silence can apparently distort time for us.

Just as optical illusions trick our eyes, auditory illusions can distort our perception of time. One example is the “one is more” illusion, where one long beep seems longer than two consecutive short beeps, even when the two sequences are the same length.

The researchers adapted the “one is more” illusion by swapping sounds with moments of silence, creating what they dubbed the “one is more” illusion.

In one experiment, nearly 1,000 study participants were immersed in ambient noise (like that of a restaurant). This noise was interrupted either by a single continuous silence or by two discrete silences, and the subjects were asked to judge the duration of the silence sequences.

When exposed to the “silence is more” illusion, the results were the same as their sound counterparts. People thought that one long moment of silence was longer than two short moments of silence.

This suggests that people perceive silence as they hear sounds. Other silence illusions, such as silence event-based distortion (a pair of tones in a silence event seem further apart in time than a pair of tones in pure silence) and eerie silence, have been tested and they all gave the same results as sound illusions. .

“We generally think of our sense of hearing as being concerned with sounds. But silence, whatever it is, is not sound, it is the absence of sound,” explains Goh. “Surprisingly, what our work suggests is that nothing is also something that can be heard.”

The illusion of a single silence is worth more

The idea wasn’t simply that these silences gave people illusions, the researchers explained. The same illusions that scientists thought could be triggered by sounds alone worked just as well when silences replaced sounds.

“There is at least one thing we hear that is not a sound, and that is the silence that occurs when sounds disappear,” said co-author Ian Phillips, professor emeritus of philosophy, psychology and brain sciences at Bloomberg.

The kinds of illusions and effects that seemed unique to auditory processing of sound are also experienced with silences, suggesting that we also actually hear absences of sound.

The results establish a new way to study the perception of absence, the team said. They plan to continue exploring the extent to which people hear silence, particularly whether we hear silences that are not preceded by sounds.

Ultimately, the sound of silence may well be more than a poetic metaphor. It is a perceptual reality, a new frontier in our understanding of how we interact with the world around us. As you go about your day, take a moment to appreciate the sound of silence. You might be surprised by what you hear.

For the curious, you can experience the illusions of silence by clicking on the demos on the study’s web page.

The results appeared in the Proceedings of the National Academy of Sciences.