Earworms: The musical itch

How does a song get “stuck” in your head? The repetitive, catchy verse from a song that your brain continually replays is known as an earworm. A 2020 study found that 97% of American college students experience earworms for over an hour. While songwriters and advertisers take advantage of earworms to increase engagement and make their music memorable, they can be intrusive and are often difficult to erase.

People have been trying to understand earworms for decades. Germans coined the term öhrwurm, translated to earworm, over a 100 years ago, and now there are many terms used to describe the feeling of when a song gets stuck in your head. Scientists often refer to this phenomenon as involuntary musical imagery (INMI), as it doesn’t require a conscious effort. 

There are many factors that cause earworms. Some people are predisposed to earworms if they have good memory, and others are more susceptible due to conditions like obsessive-compulsive disorder (OCD). Repetition and musical patterns underlie the brain’s desire to replay the verses. A study by Dr. Emery Schubert and his team suggested that the architecture of the brain allows these patterns to emerge. They found that earworms are triggered by recency, familiarity, and boredom. Schubert says that when the brain wanders, it can land on verses that were encoded by repetition and recency.

It isn’t completely understood how these repetitive phrases are encoded in the brain, but some believe it has to do with the way the brain processes memory. Dr. David Kraemer and his team at Dartmouth College played a song for participants and then interrupted it, observing the activation patterns in the brain. They found that within the auditory cortex, where sounds are processed, the part that is active while listening to the music was reactivated when participants imagined the remaining portion of the song. Kraemer describes the auditory cortex as our imagination’s “MP3 player.”

“Musical earworms are normal, and are an interesting foray into the way the brain processes imagination and memory.” 

What makes a song likely to become an earworm? There are databases that have classified songs as INMI, and a study published by the American Psychological Association investigated the characteristics that make a song likely to get stuck in people’s heads. They found that INMI songs had higher tempos and common global melodic contours, which are the sequences of pitches that create a distinct shape when drawn out. Songs like “Smoke on the Water” by Deep Purple and “In the Mood” by Glenn Miller are IMNI tunes with an arch shaped contour. 

The risk for earworms increases during certain emotional states, such as exhaustion and burnout. Additionally, people who suffer from anxiety, post-traumatic stress disorder, or OCD are more likely to experience earworms that cause major disturbances in their lives. Dr. Claire Arthur, an assistant professor at the Georgia Institute of Technology’s School of Music, says their brains are wired to ”reflect and reflect and reflect.” 

The big question is how to erase earworms. Scientists suggest completing the song, distracting yourself, and switching up your music. However, it’s not recommended to try to suppress the “cognitive itch,” as Dr. James Kellaris, assistant professor at the University of Cincinnati, says. He cautions that the more people fixate, the harder it is to actually let go. Musical earworms are normal, and are an interesting foray into the way the brain processes imagination and memory.