Most people think of ear-wiggling as a quirky trick, but new research suggests that human ears still attempt to move when focusing on sounds. While our ears appear static, scientists have discovered that traces of an ancient auriculomotor system—the ability to orient ears toward sound—are still present in the brain.
A study found that certain muscles around the ear activate when people concentrate on distinguishing sounds, even though modern humans lack the ability to swivel their ears like many other mammals. This unexpected “neural fossil” sheds light on how our evolutionary past continues to shape our brains and behavior.
A Vestigial System Hidden In The Human Brain
In many animals, ear movement plays a crucial role in detecting and localizing sounds. Cats, horses, and dogs all use this ability to enhance their hearing, focusing on noises without turning their heads. However, humans lost this skill approximately 25 million years ago, making our ears largely immobile.
Yet, the latest research indicates that the neural circuits controlling ear movement remain partially intact. Lead author Andreas Schröer and his team discovered that although most humans cannot voluntarily move their ears, the associated muscles still activate in response to auditory effort.
“Our brain retained some of the structures to modailyve the ears, even though they apparently are not useful anymore.” Schröer explained. The study suggests that, while human ears no longer physically pivot toward sound, our brains still “try” to engage those long-dormant muscles when listening intently.
The Experiment: Testing Our Hidden Ear Reflex
To investigate this phenomenon, researchers asked 20 participants to listen to an audiobook while background audio—such as a podcast—played at the same time. The difficulty of distinguishing the audiobook from the background noise varied across three scenarios:
- Easy: The audiobook was much louder than the podcast, with clear differences in pitch.
- Medium: The podcast volume increased, making the distinction harder.
- Difficult: Two podcasts played simultaneously at a higher volume, with one matching the audiobook’s pitch.
Participants, who wore electrodes to measure muscle activity, were also asked to rate how much effort they exerted trying to focus on the audiobook.
The Surprising Results
The study found that as listening effort increased, so did activity in the auricular muscles—specifically the superior auricular muscles (which lift the ear) and the posterior auricular muscles (which pull the ear backward).
Interestingly, these muscles responded differently based on sound direction. When audio came from behind, the posterior auricular muscles showed more activation, mimicking how animals would move their ears toward an unseen sound source.
Even more fascinating, none of the participants had the ability to voluntarily move their ears, meaning these muscle activations occurred subconsciously.
Why Does This Matter?
This discovery highlights the remnants of evolutionary adaptations still embedded in our nervous system. While the movements are imperceptible, they indicate that our brains are still wired to engage an outdated survival mechanism.
“The ear movements that could be generated by the signals we have recorded are so minuscule—or even absent—that there is probably no perceivable benefit,” said Schröer. “So we think that this vestigial auriculomotor system is ‘trying its best,’ but probably doesn’t achieve much.”
Could Humans Learn To Move Their Ears Again?
Though most people can’t move their ears voluntarily, some individuals can—suggesting that the neural pathways are not completely lost. Research has shown that with practice, some people can develop the ability to wiggle their ears, much like how people train themselves to raise one eyebrow.
While this study focused on involuntary ear movements, it raises intriguing questions about whether the human brain could reactivate this long-dormant skill with training. Could future experiments unlock our inner feline and restore ear mobility?
What This Tells Us About Human Evolution
The findings contribute to a growing body of research on vestigial reflexes—traits inherited from our ancestors that have lost their original function. Other examples include:
- The palmar grasp reflex in infants, a remnant from primates who needed to cling to their mothers.
- The appendix, once crucial for digesting fibrous plant material, now mostly redundant.
- Wisdom teeth, which were useful for early humans with tougher diets but often cause issues today.
Each of these quirks tells a story about our evolutionary past. The auriculomotor system might not make much of a difference in modern life, but its persistence in our neural circuitry is a testament to how the brain retains ancient functions long after they stop serving a purpose.
This study is a reminder that even as we advance technologically and intellectually, our biology still carries echoes of the past. Whether or not humans will ever regain the ability to move their ears is uncertain—but for now, our brain still remembers how.
