If the whole Yanny versus Laurel debate has taught us anything (it was most definitely "Laurel," by the way), it's that our brain has a way of playing tricks on us. To learn more about our body's ability to play mind games — literally — researchers looked into the phenomenon of the Speech-to-Song Illusion. As the name implies, our brains will hear spoken words but interpret them as songs. Give these phrases a listen and prepare to have your mind blown.
In the video above, you can hear researcher Diana Deutsch speaking. In 1995, Deutsch was editing the spoken commentary on her album Musical Illusions and Paradoxes when she noticed that the phrase "sometimes behaves so stragely" began to sound as if it were sung rather than spoken when played over and over again.
"The illusion occurs when a spoken phrase is repeated — but after it's repeated several times it begins to sound like it's being sung instead of spoken," Michael Vitevitc, the chair of psychology and a professor at Kansas University, explained in a recent study published in the journal PLOS One. "Musicians in the '60s knew about [it] and used [it] to artistic effect — but scientists didn't start investigating it until the '90s."
To understand why this phenomenon occurs, Vitevitc and his colleagues put 30 KU students through a series of six listening tests. "We looked at the word nodes and singled out phrases that had a lot of similar-sounding words. We tried to take out words altogether by using Spanish words with non-Spanish speakers. We tried focusing on the syllables and number of syllables. We looked at different characteristics, like is it the word that matters or the number of syllables?"
Below is an example of a word set the Kansas students heard during the study.
So how do you explain this Speech-to-Song Illusion? Your brain has "word nodes" (or "word dectectors") and "syllable nodes" (or "syllable detectors"), Vitevitc said. The brain behaves like a muscle, so it can get tired out. That means that when it hears a word or phrase repeated over and over, the "word nodes" get worn out. But the brain still detects "syllable nodes," because syllables give a word its rhythm. Though your "word nodes" are fatigued, your "syllable nodes" are still chugging along. As a result, your brain shifts the cadence of the phrase in your head to one that's more songlike.
"You've got word detectors and syllable detectors and, like with lots of things in life, as you use them they're going to get worn out — like your muscles. As you use them, they get tired," Vitevitc said. "Like with muscles, you have a type of muscle for short bursts of sprinting and also muscles for endurance, like running a marathon. Word nodes are like sprinting muscles, and syllable nodes are like endurance muscles."
In short, it's all about perception. You can tell the difference between singing and speaking, but when you loop a word or phrase, your brain magically transforms the listening experience. Pretty neat, right?