Humans were thought to be unique as a species in that we use both halves of our brains to "distinguish different aspects of sound," as Georgetown neuroscientist Stuart Washington puts it. Turns out we're not as special as we thought. A type of bat also displays this hemispheric specialization when it comes to sound processing, Washington has discovered. In both humans and Parnell's mustached bats—a species that lives in an area ranging from Mexico to Brazil, RedOrbit reports—the left hemisphere handles quicker sounds, while the right deals with slower ones, a press release reports. For humans, the right hemisphere "may allow us to identify who is speaking, to gauge their emotional state via tone of voice, and to tease out pitch in music," Washington notes. As for the left hemisphere, "men largely use just the left hemisphere" to process language, while women use both hemispheres to do so, Washington says.
In mustached bats—named based on the hair springing from the sides of their snouts, Animal Diversity Web explains—the right hemisphere's slower processing is used for sonar, "which relies on detecting small changes in frequency," says Washington, senior author of the study in Frontiers in Neuroscience. The left is used "to distinguish communication sounds from each other, because (the bats') communication sounds have rapid changes in frequency." All this is more than just a matter of interest: The findings could help study human language disorders, especially since some study techniques "can only be permitted in animals," Washington adds. (Researchers are also learning more about how porpoises use sound—a lot like a flashlight.)