Babies’ Ears Beat to Different Drummers

The right ear of a baby reacts faster and more accurately to speech and the left ear prefers music, UCLA and University of Arizona scientists who tested 7,000 babies reported in the journal Science this week.

Such ear preferences occur in adults as well and reflect differences in brain structures on opposite sides of the cortex used to process sound. But those brain structures are not apparent until at least four months of age, suggesting that the ability to tell speech from song may originate in a part of the brain, such as the brainstem, that is far more primitive than the cortex.