Subtle vibrations in the ear reveal gaze direction

Scientists from Duke University in the US have explored what insight vibrations within the ear canal can provide about gaze direction.

In research published in Proceedings of the National Academy of Sciences, researchers explored whether subtle auditory signals contain detailed information about eye movements.

A group of 16 study participants were asked to follow the direction of a green dot on a computer screen without moving their heads. Vibrations within the ear canal were recorded using a microphone-embedded pair of ear buds.

After analysing recordings of gaze direction in tandem with the auditory recordings, the scientists discovered unique signatures for different directions of movement.

“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,” Professor Jennifer Groh shared.

Research completed by Groh and colleagues in 2018 found that the ears make small noises when the eyes move.

It is thought that these sounds are created when eye movements stimulate the brain to contract muscles that dampen loud sounds, or the hair cells that amplify quiet sounds.