A recent study published in Frontiers in Neuroscience has found that the little muscles controlling human ear-wiggling movements flex when people strain to hear. The superior auricular muscles, which enable us to wiggle our ears unconsciously, activate in response to sound, particularly when trying to pinpoint a specific noise in a noisy environment.
This mechanism is thought to be a remnant of our evolutionary past, when our ancestors relied heavily on their hearing for survival. In the study, researchers recruited 20 participants with normal hearing and attached electrodes to track electrical activity in their ear muscles while they listened to an audiobook and a distracting podcast.
The results showed that the posterior auricular muscles fired up more when sounds came from behind the participant, suggesting a possible vestigial trait that once helped our ancestors detect sounds from outside their field of view. The superior auricular muscles also became more active as the listening challenge grew more difficult, which may indicate a correlation with listening effort.
However, experts have expressed caution in interpreting these findings, suggesting that the response might instead reflect arousal or noise frustration rather than conscious listening effort. The study’s authors hope that their research will lead to practical applications for improving hearing-aid technology in the future, such as integrating artificial intelligence that can sense and decode muscular movements.
Source: https://www.livescience.com/health/anatomy/vestigial-human-ear-wiggling-muscle-actually-flexes-when-were-straining-to-hear