Our brains have a strange preference for happy sounds coming from the left

If you’re having a nice conversation, no one will laugh at your jokes. It may not be your fault, but you are simply on the wrong side. Our brains react more positively to pleasant sounds coming from the left.

Swiss researchers Discover Our brains have a strange preference when it comes to the sound of sound. According to brain scans of 13 adults, a positive sound, such as laughter, triggers more neural activity in the auditory center of the brain when it comes from the left rather than the right. It suggests that the human auditory cortex is tuned not only to the nature of sound, but also to the direction it comes from.

Not even that is surprising
It is not clear why left-handed laughter is more difficult to come by. The experiments only looked at changes in the activity of a brain region. So more simply happens in a brain scan with a positive sound coming from the left and less if it sounds from the right. But what that means for someone’s perception of that sound, for example, is also still unknown.

However, the results aren’t entirely surprising. Outside previous search It has already been shown that the left ear is better at detecting the emotional tone of a person’s voice than the right ear. This in itself is an amazing result. Since the left ear relays information to the right part of the auditory cortex, the idea was that the right hemisphere might actually be better at processing emotions than the left.

From left to right
But this new study shows that may not be the case. Participants heard cheerful sounds coming from three different directions: left, right and centre. Both parts of the auditory cortex were activated. But the difference was huge. Recordings that participants heard only on the left side elicited a much stronger neural response. “This wouldn’t happen if the positive voices were coming from the center or the right,” says neuroscientist Sandra Da Costa.

And most importantly: “We were also able to show that neutral or negative vocal sounds, for example meaningless sounds or frightened screams, are not associated with the left side.”

Evolutionary interpretation
The direction of sound can certainly have an effect on our experience of it. Think of the siren of an ambulance coming toward you and then driving away. For example, a looming voice sounds sharper and more ominous than a receding one. Moreover, the person is more stimulated by noises that come from behind, for example.

There is a logical evolutionary explanation for a higher sensitivity to sound from a particular direction. In the past, it was undoubtedly good for your chances of survival if you were very alert to noises coming at you from behind. But it is difficult to explain the preference for the positive emotional voice coming from the left. Some brain functions are found more on the left side of the brain than on the right and vice versa, but in this case this did not seem to explain the findings.

Left hand preference
“It is currently unknown when left-affirmative voice preference emerged in human evolution or to what extent it is unique to humans,” said neuroscientist Stephanie Clark. “Once we know that, we can speculate whether it is related to left- or right-handed preference or the asymmetric arrangement of internal organs.”

In short, much remains unclear and more research is sorely needed into why we are so keen to hear happy voices coming from the left. Until then: If you want people to be more confused about your jokes, whisper them in their left ear.