By Julia Schmitt

Getting music stuck in our heads is something that we can all relate to. This phenomenon has been documented for centuries, well before recorded music. The German word ohrwurm (literally ‘earworm’) was coined for this in the 19th century. Researchers have found that 98% of people experience ohrwurms. David Kraemer a cognitive scientist at Dartmouth University suggests the remaining 2% are probably lying.

In 1952 a study was conducted by Penfield, that would struggle to get ethical approval today, and it found that patients replayed familiar music in their mind when electric currents were delivered to their brains. Recent research using more sophisticated and less unpleasant measures has found that humans can very accurately reproduce and imagine the tempo, pitch and timbre of previously heard sounds; which reveals what humans have very good auditory memory for music. This could explain why catchy songs about coconuts tend to replay in our heads rather than the taste or image of coconuts.

Furthermore, researchers have shown the more ‘victims’ listen to music the more likely they are to experience ohrwurms. Studies of brain function demonstrate areas involved in music perception and appreciation are active during ohrwurm episodes. Also, contrary to popular opinion ohrwurms occur more for songs we like rather than those we hate. It seems playing songs in our heads, even though it may annoy us, is very rewarding for our brains.

Ohrwurms have also been associated with memory, particularly brain regions involved in the perception of pitch and timing of sound. While these structures are primarily used for voluntary musical imagery (e.g. deliberately playing a song in our minds) they could also contribute to ohrwurms. This is proposed to be because brain cells and brain pathways are always active even when not directly in use. Occasionally this random activity will by chance generate the same pattern of brain activation as when listening to music. Therefore, we often hear songs in our heads more when we’re zoned out, bored or not focused, like in dull staff meetings or when riding the bus. Ohrwurms could just be a side effect of our active hearing brain.

So, if ohrwurms happen to everyone why do some suffer more than others? Studies have found those bothered by ohrwurms had smaller brain regions responsible for inhibiting the random activity in brain pathways that may generate ohrwurms. This means some people may be less able to ignore ohrwurms even before the songs are heard in their minds. Also, music conveys a lot of emotion and causes us to feel deeply, and not unexpectedly research shows auditory areas talk to other brain centres that govern how we feel. This means different people may have a stronger reaction to music than others because of the way their brains are wired.

Ohrwurms are inherently rewarding for our music loving brains and occur as a side effect of our good auditory abilities. However, some people may be more in-tune to the emotion conveyed by music (good or bad) and less able to ignore ohrwurms. Unfortunately, there doesn’t seem to be a cure on the way anytime soon.