The human brain shows a strange preference for sounds heard in the left ear.

We seem to want someone to pay attention to the words we say we need to talk to his left ear, surprisingly. But only if what we say is “positive”. At least that’s what a new study says.

it happens that, with a mysterious procedure, our brain shows a strange preference bias and better perception of the voices we hear through the left ear. Especially if the voices are beautiful.

The discovery was a real surprise. That wasn’t wanted. Neuroscientists from the Swiss Federal Institute of Technology Lausanne (EPFL), University Hospital Lausanne and the University of Lausanne, all in Switzerland, used brain scans to measure the activity of the auditory cortex.

And they found that positive human sounds, like laughter, trigger a increased neural activity in the auditory system of the brain when heard from the left side, suggesting that the human auditory cortex is highly tuned to the direction of sounds that make us happy.

It’s not clear why there is a preference: the experiments have focused solely on changes in auditory cortex activity. It is not known how this change translates into the perception of those sounds. by someone and should be tested in future research.

Previous studies have shown that the left ear can identify more easily the emotional tone in someone’s voicesuggesting some underlying specialization.

Since the left ear sends information first to the right hemisphere of the auditory cortex, it was assumed that the right side of the brain should be better to process emotions than the left side.

But these recent findings, which were published in Frontiers in Neuroscience. they suggest may not be the answer correct.

When study participants heard happy human vocalizations from three different directions, left, center, or right, both sides of his auditory cortex were activated.

However, recordings heard only on the left side caused a much stronger neurological response.

“This does not occur when vocalizations come from the front or right”, says neuroscientist Sandra da Costa from EPFL.

“We also show that vocalizations with neutral or negative emotional valence, for example gibberish or fear cries, and sounds different from human vocalizations they do not have this association with the left side“.

The direction of a noise can obviously affect the quality of that sound: for example if you think of an ambulance siren approaching your position and then moving away. AND it can also affect our perception.

Previous studies have shown that approaching sounds are often perceived as more threatening and exciting than receding sounds. And the evidence suggests it a person gets excited more easily when a sound comes from behind.

Greater sensitivity to certain noises coming from certain directions has a large evolutionary sense. The survival of a human being in past millennia would surely have depended be more suspicious of sounds sneaking up from behind.

But a sinister bias of emotion in human voices not so easily explained.

It is known that some brain functions reside more in the left side of the brain than in the right, and vice versa, but in this particular case, which does not seem to explain the results.

While the right hemisphere of the auditory cortex showed a stronger response to happy human voices in a region called L3, both sides of the brain they were triggered by sounds in experiments.

“At the moment it is not known when the primary auditory cortex preference appears from positive human vocalizations from the left during human development and whether it is a uniquely human trait,” said neuroscientist Stephanie Clarke, also a study participant.

“Once we understand this, we can speculate if it is related with the asymmetrical arrangement of the internal organs”, concluded the specialist.

Source: Scientific Advisory