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Humans 'prick' their ears up just like cats and dogs when they hear interesting sounds, scientists find

It is yet another thing we have in common with our pets -  Paul Marriott
It is yet another thing we have in common with our pets - Paul Marriott

The cry of 'prick your ears up' is a familiar sound to day-dreaming children, but until now, no one believed humans really could move their ears like a dog or a cat.

However, scientists have now found we have more in common with our household pets when we thought.

Researchers from the Systems Neuroscience & Neurotechnology Unit in Germany have found for the first time that we make minute, unconscious movements of our ears that are directed towards the sound want to focus our attention on.

The study, published in the journal eLife, measured electrical signals in the muscles of the vestigial motor system in the human ear.

Despite the function to move the outer part of our ears evolved out of human ancestors 35 million years ago, the brain still sends signals to the ears to try and 'prick' them up when a sound is interesting enough.

Neuroscientist Professor Danial Strauss, who led the research, said: "The electrical activity of the ear muscles indicates the direction in which the subject is focusing their auditory attention.

"It is very likely that humans still possess a rudimentary orientation system that tries to control the movement of the pinna (the visible outer part of the ear). Despite becoming vestigial about 25 million years ago, this system still exists as a 'neural fossil' within our brains".

The researchers were able to record the signals that control the tiny movements of the pinna using a technique known as surface electromyography (EMG).

They used sensors attached to the subject's skin, to detect the electrical activity of the muscles responsible for moving the pinna.

Subjects then had two types of attention tested, with automatic reaction when we hear unexpected sounds measured by exposing them to noise at random intervals while they silently read a monotonous text.

Goal-oriented attention also caused ears to 'prick'; to test this, the participants were asked to listen to a short story coming from one laterally positioned speaker, while ignoring a 'competing' story from a speaker located on the opposite side.

Professor Strauss said this research could help with the development of better hearing aids.

He explained: "These devices would be able to amplify the sounds that the wearer is trying to hear, while suppressing the noises that they are trying to ignore. The device would function in a way that reflects the user's auditory intention."