The human eardrums, it turns out, move, focusing the hearing in the same direction as his eyes look. The reason for this phenomenon is incomprehensible, scientists write, but the prospects for such an opening are enormous.
Jennifer Groh and her research team at Duke University used microphones placed in the ears of people to study how the position of the tympanic membrane changes during the saccade – rapid, strictly coordinated eye movements that occur simultaneously in the same direction. The person does not notice this, however our eyes perform several saccades per second in order to make the most of the surrounding environment.
Investigating 16 people, scientists found changes in pressure in the ear canal, which was probably caused by contractions of the muscles of the middle ear, pulling the eardrum. Such changes in pressure indicate the following: when a person looks, for example, to the left, the eardrum of the left ear is pressed into the ear a little deeper, and the right one – slightly protrudes. These changes in the eardrums started an average of ten milliseconds before the eyes began to move, and continued for several tens of milliseconds after the eyes stopped.
“We believe that even before the actual movement of the eyes, the brain sends a signal to the ears:” I ordered my eyes to move 12 degrees to the right, “Groch says, movements of the eardrum that follow the changes in focus can prepare the ears of a person to perceive sounds from a certain Directions, scientists suppose.
According to David Bulkin (Dave Bulkin) from Cornell University, never before the position of the eyes was not considered in this vein. In other words, it affects the ears.
But how exactly the movements of the eardrums affect what we eventually hear are completely incomprehensible, says Groh. According to one suggestion, the reason why the eyes and ears move “in tact” is that it helps the brain to be more aware of what we hear and see.
The discovery can lead to the creation of more sophisticated hearing aids, the scientists summarize. Now they amplify all sounds equally, regardless of where they come from.
At the same time, the brain of a person with a healthy ear can focus on the sounds produced by another person even when talking in a crowded restaurant. In other words, you can easily focus on talking with one person while ignoring others’ words in a public place, Groh notes.
“I could imagine a mechanism that can be included in a hearing aid that captures signals about eye movements that have focused their attention on a new location and try to amplify the sound from this place,” the researcher argues. However, before the advent of these developments, researchers will need to conduct many more studies.