Before, the muscles of our ears allowed us to rotate them, today, according to a study, they no longer have this role but always help us to hear when there is a lot of noise.
- The muscles which connect the outer part of the ear to the skull and the scalp were used, before, to rotate the ears.
- It was believed that they had not therefore been used by humans for millions of years.
- But researchers have just discovered that they still serve us to hear sounds when we concentrate, especially when the environment is noisy.
Can you move your ears? If this is not the case, rest assured, this is completely normal, because there are only 10 to 20 % of humans get there! This feat is due to the muscles which connect the outer part of the ear – also called pavilion – with skull and scalp.
Ear muscles improve our auditory capacity
Apart from these people, these muscles have not been used by the human species for about 25 million years. “” “The evolutionary pressure to move the ears has ceased because our visual and vocal systems have become much better”Explains the American site Popular Science. In any case, this was what we thought, until the publication of a new study.
During their work, published in the journal Frontiers in Neuroscience,, Researchers have discovered that these muscles were still useful to us! They help us to distinguish close sounds, especially when we are in a noisy environment.
“” “There are three large muscles which connect the pavilion from the ear to the skull and the scalp and which are important for the movement of the ears ”, Indicates Andreas Schröeer, co-author of the study and neuroscientist of the University of Saar in Germany, in a press release.
To confirm the role of these muscles, Andreas Schröeer and his team of scientists asked twenty volunteers, who had no hearing problems, to wear electrodes. These devices measured the activity of the ear muscles.
The participants then had to listen to an audio book and podcasts from speakers placed in front or behind them. In all, there were 12 five -minute tests, with three levels of difficulties.
Activation of these muscles is not reflex
Results: these muscles were activating at each level and more, when there was a lot of noise! The researchers therefore concluded that they were still useful to us to focus on listening and, above all, to hear and distinguish sounds in a noisy environment.
“These muscles, in particular the higher atrial muscle, present a more important activity during intense listening tasks, underlines Andreas Schröeer. This suggests that when these muscles are activated it is not a reflex, but that they participate in a mechanism of effort of attention, especially in noisy environments”.
In the future, scientists plan to continue their research to confirm their results and possibly discover new functions in the muscles of our ears!
