A so-called “useless” muscle, which enables some individuals to wiggle their ears, actually activates when straining to hear sounds, revealing a fascinating link to our evolutionary past.
Humans inherited remnants of the ability to pivot their ears from their ape ancestors, who lost this capability millions of years ago. The auricular muscles and associated brain neurons still linger in our anatomy, sparking curiosity among scientists regarding their function.
In a groundbreaking study conducted by researchers at a German university, it was discovered that these auricular muscles activate in response to sounds coming from different directions, particularly when individuals are focused on listening.
To investigate this phenomenon, 20 participants, aged 22 to 37 with typical hearing, underwent a series of hearing tests that required them to concentrate on an audiobook while their auricular muscle activity was monitored using skin sensors.
The study progressively increased difficulty: a quiet male podcast was played during the audiobook initially, followed by a quieter female voice, and culminating in both background sounds being amplified for the toughest test. Noteworthy findings indicated that the superior auricular muscle exhibited maximum activation during the most challenging test scenario.
This observation highlights the significance of this yet often overlooked muscle during concentrated listening efforts. The researchers suggest that measuring auricular muscle activity could serve as an objective metric for assessing listening effort, potentially aiding the future development of improved hearing aids designed to reduce listening strain.
However, further research with a broader participant pool, including different age groups and varying hearing abilities, is necessary to reinforce these findings. Additional factors, such as eye movements and facial expressions, which may influence auricular muscle activity, also need to be considered in future studies.
The researchers emphasize the need for ongoing investigation into this “neural fossil” to better understand its functions and how it can be utilized for advancements in auditory health.
