98 percent of people have experienced the phenomenon of a ‘sticky’ song getting stuck in their heads – the earworm. It’s really no surprise with all the music playing everywhere around us: from the supermarket radio and elevator speakers to your neighbor’s headphones on the subway. Hardly ever will you yourself pick what plays next on repeat in your brain’s radio station. So, what happens in the brain exactly, and what makes some songs so ‘earwormy’?

The earworm (or stuck song syndrome) is no new subject. People have been experiencing them since the beginning of civilisation. But with the invention of music players like the phonograph, jukebox and radio, as well as the increasing popularity of listening to music as a leisure activity, they’ve been on the rise.

This phenomenon first appeared in literature at the end of the 19^th century in Mark Twain’s "A Literary Nightmare” and has since been subject to psychological and medical research for about a hundred years. The use of the word earworm was inspired by the German word Ohrwurm, becoming popular in the German language in the 1950s. The expression originates from the earwig insect which was misbelieved to crawl into your ears when you sleep – just like the catchy tunes.

INMI: PING-PONG EFFECTS IN THE AUDITORY CORTEX

In the 1980s, neuroscientists officially gave a name to this involuntary effect of music getting stored in and retrieved from the memory: Involuntary Musical Imagery (INMI).

20 years ago, Kylie Minogue created a song about what happens with earworms and at the same time contributes to the phenomenon with this catchy tune

Studies show that highly sensitive people with a lower threshold for stimuli are more likely to experience INMI. Music lovers and musical people get earworms more frequently and more intensely. Professional musicians experience earworms the most frequently. 

By studying MRI scans during listening sessions and breaks, scientists have discovered what’s happening in the brain during an earworm takeover: imagine a ping-pong match between the brain centers for sing-along and hearing. The centers in the temporal lobe that are responsible for internal hearing send stimuli to the centers in the frontal lobe responsible for sing-along, which then send stimuli back to the centers responsible for internal hearing. This creates an endless loop difficult to break, called INMI.

WHEN DO THE EARWORMS GET YOU? 

The more sophisticated your taste in music is, the more sophisticated your earworms can get – way beyond radio hits! Even just seeing the lyrics of a song can make our brains sing along inside. We’re more prone to catch an earworm after we stop focusing, in moments when the working memory is inactive, when we’re relaxed, when work is finished or when we’re a bit sleepy. Physical activity has also been shown to be a factor to open your mind for sound memories. 

Songs that evoke memories are more popular among earworms.

Sometimes an earworm even appears without being exposed to the actual music. This can happen when we experience stimuli that are connected to the memory of the song: seeing or smelling something may trigger a melody. Another way earworms appear is when known songs are automatically continued in the mind after the sound stops.

Instrumental songs have a harder time getting playtime on the brain radio, because lyrics activate bigger parts in the brain than melodies alone; words strengthen the memory of the melody itself. But again, it does somewhat depend on the listeners musicality. Often the hook in a song is as important to their catchiness as the lyrics.

Usually, the music in the brain vanishes after an hour of two, but it’s not uncommon that a song remains with the listener for up to a whole week. More than a few people have even sought medical help for long-term earworms from doctors and scientists.

ONCE, TWICE, MELODY – FACTORS THAT CREATE INVOLUNTARY MUSICAL IMAGERY

Listening to a melody just once or twice can enable the brain to sing along in thought; chances of catching an earworm rise significantly after six repetitions.

Comparing different scientific resources on what exactly makes a song earworm material, we’ve collected the most important factors.

POPULARITY, RECENCY AND REPETITION

When a song is very popular, your chances of hearing it are also higher. So naturally, it’s more likely to become a sticky song occupying your head. Two times is the minimum number of repetitions you must listen to a song to be able to recall it involuntarily; listening to it more than six times gives you drastically higher chances of getting stuck with it. New music will hardly ever stick to you right away – unless it’s self-composed. 

In recent years, Tame Impala’s Kevin Parker has perfected the art of writing songs highly irresistible to the brain – isn’t it true?

FAMILIARITY

Studies show higher brain activity and additional dopamine production when a song is known to the listener. It doesn’t even matter whether you like the song or not; the positive effects just don’t appear when a song is unfamiliar. Thus, the chance to become an earworm increases the more often a song is listened to, explaining why music played the radio and, on the charts, becomes common earworm material.

MELODIC STRUCTURE

The catchiest earworms are simple, universal melodies that we can sing along to effortlessly. A rhythmic structure that’s easy to dance to helps, too. Studies show that closely spaced intervals in the notes with a longer duration increase a songs’ earworm potential.

If the lyrics are simple and repetitive, and the sound and rhythm is upbeat and steady, we have the best ingredients for an earworm. Research shows that falling melodies that are then rising again are also earworm-catchy. Predictable melodies that suddenly surprise you with an unpredicted twist, while still easy to sing along to often gets trapped in your memory as well.

A melody with notes that first go down and then up, paired with simple repetitive lyrics make for great head radio material. 

EMOTION

Songs that awaken nostalgia and memories are more likely to get stuck in your head because of the emotions you feel listening to them. This is especially true if the song also has emotional lyrics about experiences that are common to most people. The music may pop back into your brain when you think about the things you first associated a song with.

INMI AND ITS HEALING EFFECTS

Earworms seem to have an impact on the psyche, just like playing music and singing. The inner musical experience has similar effects to actual musical activity because they stimulate the same neuronal areas and release the ‘feel-good’ hormone dopamine that helps to improve anxiety and depression.

Metronomy’s “The Look” from 2011 is so catchy that even the remix is an earworm – your brain automatically fills in all the gaps.

THE CURE: DON’T LISTEN TO THE CURE – OR ACTUALLY, DO IT!

There are some studies showing that the reason we can’t get a song out of our head is because the brain obsesses over completing something incomplete, like the fragments we heard or remembered. Surprisingly, listening to the song in entirety and engaging with it can actually resolve the problem. Even Neil Young heals himself from songs on repeat in his mind by playing and singing the unwanted music out of his head.

And here is The Cure: upbeat, danceable, with a catchy keyboard melody with closely spaced intervals that Billboard magazine calls “a brain-burrowing call-and-response synth hook”

Focusing on something that requires more brain activity will help fade out the music as well. An easier tip? Chewing gum. The continuous movements of the jaw are said to be effective at stopping the singing in your head, possibly also because actual singing gets harder with a gum in your mouth.

Even angular music can be catchy to the musically experienced brain when paired with familiar themes and styles like synth pop from the 1980s.

Cover Credit: KoolShooters/Pexels

Writer | Suzee Lee

Suzee Lee is a writer and music lover, based in Berlin. She has a master’s degree in cultural studies, worked in the art scene as an online editor and founded the music copywriting agency repeat redaktion. She loves to share her musical obsessions as a music journalist, radio host and DJ, on her webzine repeat magazine – and directly to her fellows by humming and singing them wherever she goes. Follow Suzee’s obsessions here.