The volatility of your ears may be more than a piece of concerts more than the skill of survival, but humans are still trying to prick their ears when listening hard, and researchers have found.
Ear movement is very important in many animals, not the least of which is their help in focusing their attention on a certain noise and knowing the direction they come from.
But while the human ear is more bright, the effects of the system of our ancestors in the ear remain in the so -called “nervous fossil”.
“It is believed that our ancestors have lost their ability to move their ears about 25 meters ago. Andreas Sharur, the main author of the Sarland University research in Germany, said:” Why, exactly, it is difficult to say. “
However, we were able to prove that the nerve circles are still present in some state, [that is] Our brain kept some structures to move the ears, although it is no longer useful anymore. “
The team previously found that the movement of these muscles in humans is linked to The direction of the voices they care about. Now, they found that some of these muscles are activated when humans strongly listen to a sound.
Writing in the magazine BoundariesThe team reported how they were asked of 20 adults without hearing problems to listen to an audio book that is played through an amplifier at the same time that podcast was played from the same site.
The team created three different scenarios: in the “easiest” scenario, the podcast was quieter than Audiobook, with a great difference in the field between the voices. In the “harder” scenario, two podcasts were played, they were, together, higher than the Audiobook book, with one of the podcasts that are spoken in a stadium similar to the audio book.
“We were interested in knowing whether the AURICULOMOTOR system in humans was sensitive to listening to the effort. Think about trying to understand what someone says in almost an empty restaurant, and try to understand someone in a very crowded restaurant.”
Each participant witnessed the three different scenarios twice. Then this is repeated with the headphone in a different position in the room. Each participant wore a group of electrodes, allowing researchers to record the electrical activity resulting from the muscles participating in the fluctuation of the ears.
After each experiment, the participants were asked to assess the amount of effort they spent in listening to Audiobook.
The results revealed that the perceived listening voltage of the participants, and the number of times they lost focus on the audio books, increased with the transmission of the scenario from easier to the most difficult.
The team found an activity in the muscles of the superior ears, which raise the ear up and out, was greater during the most difficult listening conditions than the easy and medium conditions. They also found that the posterior ear muscles, which pulled the ear, were more active when the voices came behind the participant more than before them.
“Almost no one [in the study] “He had the ability to move their ears voluntarily, and therefore our results are not related to a person’s ability to do so,” although he indicated that other research showed that people could learn to transfer their ears.
While the study is small, and it needs to be repeated in a larger and more diversified group, the team said the results provided visions.
Sherwar said: “The ear movements that can be generated with the signs that we have recorded are very small – or even absent – so that there is no reasonable benefit,” Sherwar said. “So we believe this archaeological Auriculumotor system” is doing its best, “but may not achieve much.”