The Brain's Peculiar Affinity for Left-Side Sounds

Neuroscientists have discovered that positive human sounds, like laughter, trigger stronger neural activity in the brain's auditory system when they are heard from the left-hand side, suggesting the human auditory cortex is specially tuned to the direction of sounds that make us happy. The left ear can more easily identify the emotional tone in someone's voice, hinting at some underlying specialization. The study suggests that heightened sensitivity to certain noises coming from certain directions makes broad evolutionary sense, but a left-handed bias to the emotion in human voices is not so easily explained.