When the study participants listened to happy human voices from all three directions, right, left, and center, both sides of their auditory cortex were activated; However, sounds that were heard only on the left side elicited a much stronger neural response.
“This did not happen when the positive sounds were played from the opposite or right side,” says Sandra da Costa, a neuroscientist at the Ecole Polytechnique Fédérale in Lausanne. “Furthermore, the experiments showed that sounds with a neutral or negative emotional valence, such as nonsense sounds, fearful screams, or sounds other than the human voice, did not have such an association with the left side.”
The direction of a sound can clearly affect the quality of the sound and even our perception of it. To better understand this, it is better to think of the sound of an ambulance moving towards you and then moving away from you.
previous studies have shown that loud sounds are often perceived as more frightening and arousing than soft sounds. Evidence suggests that a person is more easily aroused when a voice comes from behind.
Extreme sensitivity to certain sounds coming from certain directions has a wide evolutionary meaning. Undoubtedly, the survival of humans in the past millennia has depended on being overly suspicious of voices that secretly approached from behind; But the left bias towards the emotions in the human voice is not easily explained.
Based on the previous findings of researchers, some brain functions are more on the left side and vice versa; But in this particular case, past findings do not seem to provide a convincing explanation for the recent discovery.
In a recent experiment, the right hemisphere of the auditory cortex showed a stronger response to happy human voices in an area called L3; But both sides of the brain were activated after listening to the sounds played in the experiment.
“It is currently unclear whether the auditory cortex’s preference for positive human sounds from the left emerges during human development or is a uniquely human trait,” says neuroscientist Stephanie Clarke of the experiment. “Once we find the answer, we can predict whether this is also related to a preference for using one hand or an asymmetric arrangement of internal organs.”
A recent study in the publication Frontiers in Neuroscience It has been published.
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