If you are having a nice chat, 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 cheerful sound coming from the left.
Swiss researchers discovered that our brains have a strange preference when it comes to voice sound. According to a brain scan of 13 adults, positive sound, such as laughter, leads to more neural activity in the auditory center of the brain when it comes from the left, not the right. It suggests that the human auditory cortex is tuned not only to the nature of the sound, but also to the direction it is coming from.
Not even that surprising
It is not clear why laughter from the left comes in harder. The experiments only looked at changes in the activity of the brain region. So simply more happens on a brain scan with 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.
That said, the results are not entirely surprising. Previous research has shown that the left ear is better at detecting the emotional tone of a person’s voice than the right ear. That in itself is a remarkable result. Because the left ear passes 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 part.
From left to right
But this new study shows that may not be the case. The participants heard cheerful voices coming from three different directions: left, right and center. Both parts of the auditory cortex were activated. But the difference was big. The recordings that the participants only heard on the left side elicited a much stronger neurological response. “This didn’t happen if the positive voices came from the center or the right,” says neuroscientist Sandra da Costa.
And even more remarkable: “We were also able to show that neutral or negative voice sounds, for example meaningless sounds or fearful screams, do not have this association with the left side.”
The direction of sound can certainly have an impact on our experience of it. Think of the siren of an ambulance coming towards you and then moving away from you. For example, looming sound also comes across as more intense and ominous than receding sound. Moreover, someone is more stimulated by noise that comes from behind, for example.
There is a logical evolutionary explanation for a higher sensitivity to sound from a certain direction. In the past it was undoubtedly good for your chances of survival if you were extra alert to noise coming at you from behind. But a preference for positive emotional sound coming from the left is more difficult to explain. Some brain functions are more on the left side of the brain than on the right side and vice versa, but in this case that doesn’t seem to explain the results.
Preference for left hand
“It is currently unknown when the left-wing positive voice preference emerged in human development or to what extent it is unique to humans,” neuroscientist Stephanie Clarke said. “Once we know that, we can speculate whether it’s linked to a left or right hand preference or the asymmetrical arrangement of the internal organs.”
In short, much is still unclear and more research is desperately needed to find out why we are so eager to hear happy sounds coming from the left. Until then: if you want people to be even more confused about your jokes, whisper them in their left ear.