New research shows that the small sounds generated within the ear by the brain contain accurate information about contemporaneous eye movements in the spatial domain: the direction and amplitude of the eye movements could be inferred from these sounds.
“You can actually estimate the movement of the eyes, the position of the target that the eyes are going to look at, just from recordings made with a microphone in the ear canal,” said Duke University’s Professor Jennifer Groh, senior author of the study.
In 2018, Professor Groh and her colleagues discovered that the ears make a subtle, imperceptible noise when the eyes move.
In their new study, the researchers found that that these sounds can reveal where your eyes are looking.
Just by knowing where someone is looking, they were able to predict what the waveform of the subtle ear sound would look like.
“Since a diagonal eye movement is just a horizontal component and vertical component, we realized you can take those two components and guess what they would be if you put them together,” said first author Stephanie Lovich, a graduate student at Duke University.
“Then you can go in the opposite direction and look at an oscillation to predict that someone was looking 30 degrees to the left.”
According to the authors, these sounds may be caused when eye movements stimulate the brain to contract either middle ear muscles, which typically help dampen loud sounds, or the hair cells that help amplify quiet sounds.
“We think this is part of a system for allowing the brain to match up where sights and sounds are located, even though our eyes can move when our head and ears do not,” Professor Groh said.
Understanding the relationship between subtle ear sounds and vision might lead to the development of new clinical tests for hearing.
“If each part of the ear contributes individual rules for the eardrum signal, then they could be used as a type of clinical tool to assess which part of the anatomy in…
Read the full article here