The Hidden Power of Ear Wiggling

Have you ever tried to wiggle your ears? It might seem like a quirky party trick, but the ability to move your ears is a remnant of a much more critical function from our evolutionary past. The auricular muscles, responsible for ear wiggling, once played a vital role in helping our ancestors tune into important sounds. These muscles are vestigial in modern humans, meaning they no longer serve their original purpose but have fascinating residual functions—especially when it comes to listening carefully.

The auricular muscles help change the shape of the pinna (the outer part of the ear), effectively funneling sound toward the eardrum. However, millions of years ago, our distant ancestors used these muscles more actively. Over time, as humans developed better visual and vocal abilities, the need to move our ears diminished, and these muscles became vestigial.

Despite their reduced functionality, scientists are now revisiting these muscles to understand their role in auditory processing. Interestingly, recent research suggests that these muscles aren’t just for show—they may still be activated when we’re trying to listen in challenging acoustic environments.

The Role of Auricular Muscles in Effortful Listening

The auricular muscles consist of three main muscle groups: the posterior, superior, and anterior auricular muscles. While many of these muscles can still move the ears slightly, their primary function in modern humans seems to be related to attentional effort when listening. According to Andreas Schröer, a researcher at Saarland University, the superior auricular muscle, in particular, shows increased activity during tasks that require focused listening.

Schröer and his colleagues conducted an experiment to observe how these muscles behave during attentive listening. The study, published in Frontiers in Neuroscience, found that the auricular muscles were activated when participants were exposed to competing sounds in a distracting environment. This suggests that the auricular muscles may still have a role in helping us focus our attention on sounds that are important or relevant, despite the fact that ear movement itself is no longer necessary for this purpose.

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“There are three large muscles which connect the auricle to the skull and scalp, and are important for ear wiggling,” Schröer explained. “These muscles, particularly the superior auricular muscle, exhibit increased activity during effortful listening tasks. This suggests that these muscles are engaged not merely as a reflex but potentially as part of an attentional effort mechanism, especially in challenging auditory environments.”

The Study: How Muscle Activity Indicates Listening Effort

Testing how hard someone is trying to listen to a sound is difficult without asking the person directly. However, a technique called electromyography (EMG) measures the electrical activity in muscles and offers valuable insights into auricular muscle engagement.

Schröer’s study used this technique to observe the auricular muscles of participants as they engaged in various listening tasks. Previous studies had already shown that the posterior and superior auricular muscles react to attentive listening, likely because they are involved in adjusting the position of the ear to better capture sounds. These muscles pull the ears backward and upward, a movement that was likely crucial in earlier evolutionary periods when humans relied more on the orientation of their ears for auditory perception.

“The exact reason these muscles became vestigial is difficult to determine, but one possible explanation is that the evolutionary pressure to move the ears ceased because we became much more proficient with our visual and vocal systems,” Schröer explained.

How the Experiment Worked

The experiment, conducted by Schröer and his team, involved 20 participants who had no hearing impairments. The participants wore electrodes on their auricular muscles to monitor their activity while they listened to different audio tracks. The experiment consisted of listening to an audiobook and competing podcast audio—either coming from directly in front of them or from behind—at various difficulty levels.

The listening conditions varied in three different modes:

  • Easy Mode: The podcast audio was quieter than the audiobook, and the speaker’s voice contrasted strongly with the audiobook.
  • Medium Mode: The podcast audio was louder and more similar to the audiobook, making it harder to focus.
  • Difficult Mode: The podcast became even louder, and the speakers’ voices became more difficult to distinguish from the audiobook.
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During each condition, participants rated their perceived effort and the extent to which they lost track of the audiobook. They were also quizzed on the content of the audiobook.

Findings and Insights

The results were telling. Schröer’s team found that the posterior auricular muscles responded to changes in the direction of sound, particularly when the audio source was located behind the participants. However, the more intriguing discovery came from the superior auricular muscles. These muscles were found to become particularly active during the more difficult listening tasks. This suggested that these muscles might be associated with the effort it takes to focus on a sound in a challenging auditory environment.

Interestingly, when participants moved from easy to medium and then to difficult listening tasks, their self-reported effort levels and the accuracy of their responses dropped in line with the increased activity of the superior auricular muscles. The results indicated that muscle activity could be used as a measure of how much effort a person was putting into listening, despite the fact that the actual ear movements were too small to make any perceptible difference to the sound itself.

“The ear movements that could be generated by the signals we have recorded are so minuscule that there is probably no perceivable benefit,” Schröer said. “However, the auricle itself does contribute to our ability to localize sounds. So, our auriculomotor system probably tries its best after being vestigial for 25 million years, but does not achieve much.”

What Does This Mean for Future Research?

The findings suggest that the auricular muscles, especially the superior auricular muscle, could provide an objective way of measuring listening effort. Although the movements themselves are too small to affect how we hear, the activity of these muscles might be linked to our brain’s effort to focus on sound, particularly in environments with competing noises.

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The researchers also pointed out that further studies will be necessary to confirm these results and explore the potential applications. For example, it would be interesting to examine how these findings might apply to people with hearing impairments or in real-world conditions where listening challenges are more complex. Additionally, exploring how the muscle strain or small ear movements might influence sound perception in hearing-impaired individuals could reveal important insights for improving auditory technologies.

“Investigating the possible effects of muscle strain itself or the ear’s minuscule movements on the transmission of sound is something we want to do in the future,” Schröer said. “The effect of these factors in people with hearing impairments would also be interesting to investigate.”

Conclusion: The Auricular Muscles and the Evolution of Listening

Although the ability to move our ears has long been relegated to a vestigial function in humans, it seems that the auricular muscles still play an unexpected role in how we engage with sound. This new research sheds light on how these muscles may help us focus our attention in noisy, distracting environments—a reminder of how our ancestors might have used their ear movements to fine-tune their hearing. While the precise benefit of auricular muscle activity remains unclear, it opens the door for further exploration into how our bodies help us process sound in complex listening environments, and how this could be applied in future hearing technologies.

Reference: Electromyographic Correlates of Effortful Listening in the Vestigial Auriculomotor System, Frontiers in Neuroscience (2025). DOI: 10.3389/fnins.2024.1462507

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