For each command, Ratcliffe recorded which way the dogs turned their heads — toward the left speaker or toward the right speaker. Even though both speakers were playing the same sounds, a clear pattern emerged.

When the dogs heard commands that still had meaningful words in them, about 80 percent of the animals turned to the right. When they heard commands, with just emotional cues in them, most dogs turned to the left.
That result sounds simple. But Andics, who wasn’t involved in the study, says the findings show something surprising: “That dogs are able to differentiate between meaningful and meaningless sound sequences.”

The study also suggests that a dog’s brain breaks up speech into two parts: the emotional cues and the meaning of the words. Then it processes these two components on opposite sides of the brain: emotional cues on the right, meaning of words on the left. (Yes, it’s opposite to the way the dogs turned.)