Many animals, including cats, dogs, and deer, will prick up their ears to listen, and they often look alert. This is true for cats, dogs, and deer. In fact, if you look carefully, you will find that the ears of these animals not only stand up, they usually also have the ability to rotate their ears slightly, which is very useful in that it allows the ears to focus on a specific source of sound so that they can hear more clearly and respond in time.
For these animals, listening carefully can mean the difference between life and death, but humans do not have this ability. Human ears are very inflexible and it is difficult to "actively" pull the ears to focus on a sound.
Maybe some people have the ability to move their earlobes, or pull their ears to move through the efforts of some facial muscles, but it seems that these have not a great impact on hearing.
Recently, a study from Saarland University in Germany found that although the human ear is difficult to actively move, when we need to listen carefully, it will move "passively" - the muscles around our ears will try to pull the ears to hear more clearly.
The study recruited 20 volunteers with normal hearing. Researchers placed electrodes on the participants' auricle muscles to pick up activity signals and played an audiobook next to a distracting podcast.
Scenarios ranged from easy (quiet podcast, tonally unique audiobook) to difficult (loud, tonally similar podcast vs. audiobook), and then had volunteers rate their listening effort and answer a quiz about the audiobook content.
The results are shocking!
As volunteers' listening tasks become increasingly difficult, theysuperior auricle musclesBecoming increasingly active, these muscles are responsible for lifting the ears upward and outward (ear-pricking manner), and the more noisy the environment, the more these muscles are activated;
in addition,posterior auricle musclesThey also responded to sounds behind the volunteers, and these muscles are responsible for pulling the ears back.
However, the recorded signals show thatThe ear movement produced by these muscle activities is very small or may not even exist., so it should have no obvious effect, just aDegenerated ear motor system.
Although almost no one can feel how hard our ears work to hear clearly, it can explain one thing. Our brains retain an ancient sound directional system and guide ear movements. Scientists call this feature "Neurofossils".
The human body actually has many "neurofossils" that have long since degenerated and no longer have practical uses, but they can still be "awakened", such as many that currently have no practical use.conditioned reflex, some are obvious, such as fingers getting wrinkled after being soaked in water.
When and why these neurofossils degenerate is often difficult to verify, the study's researchers noted.Human ear motor system may have disappeared about 25 million years ago;
And the reason why it degrades isIt's likely that because our ancient ancestors became more and more dependent on their visual and vocal systems, the evolutionary pressure to move their ears to hear better became smaller and gradually disappeared (we no longer relied on discerning subtle differences in sound).
at last
This is a newly discovered "neurological fossil" in the human body, but it may not only be a conditioned reflex, because it is related to our auditory system. It may be part of the attentional effort mechanism or part of the function of hearing.
However, the researchers in this study also pointed out that the current study sample is too small to draw conclusions.
Future research could explore whether this ear system also plays a role in people with hearing loss, and could also examine how these muscles interact with other aspects of auditory processing.
Original report:
https://www.zmescience.com/science/news-science/humans-lost-the-ability-to-wiggle-their-ears-25-million-years-ago-but-your-ear-muscles-still-try/