Evolution has left humans with many vestigial traits—remnants of once-useful biological features that serve little or no modern purpose.
One such example is the muscles around our ears, which in many animals help direct hearing toward sounds of interest.
While humans lost this ability millions of years ago, new research suggests that these muscles may still serve a subtle but important function.
Ear Muscles and Focused Listening
A study conducted by researchers from Saarland University, the University of Missouri, and WS Audiology found that the muscles responsible for ear movement still activate when we try to focus on specific sounds amid background noise.
As reported by DziennikNaukowy.pl, scientists used electromyography to track muscle activity in the ears while participants listened to an audiobook with varying levels of background distraction.
The results showed that the upper ear muscle became increasingly active as the listening task became harder, suggesting that these muscles may be part of our brain’s auditory attention system.
An Evolutionary Leftover from 25 Million Years Ago
Millions of years ago, our ancestors had nine ear muscles that allowed them to direct their ears like modern-day cats and dogs. Over time, as humans relied more on sight and speech, the evolutionary need for ear movement diminished.
Despite this, the study found that neural circuits for ear movement still exist, even if they no longer serve a clear functional purpose.
Do These Muscles Actually Help Us Hear?
The researchers concluded that while ear muscles activate in response to challenging listening tasks, their movement is so minor that it likely has no real impact on hearing ability.
However, the study suggests that measuring ear muscle activity could become a useful way to track auditory effort—potentially benefiting research into hearing loss and cognitive strain in noisy environments.
Even after 25 million years, it seems our ear muscles are still trying to do their job, even if they don’t achieve much anymore.
