The researchers found some notable differences between dog and human brain responses. In people, just 3 percent of our auditory cortex responds more strongly to non-voice sounds than to voice sounds. In dogs, it’s 48 percent. “The human auditory system is optimized to process vocal sounds, and the dog auditory brain in general is not as specialized,” Andics says. As to the implications of that difference, who knows. He speculates that it could be what allowed us to develop language.

Andics is more excited about the ways in which the dog and humans brains are similar. It turns out that both species have an area of the brain that is tuned to the “emotional valence” of a voice, meaning it responds more strongly to positive emotions than negative emotions. And for this region, it doesn’t matter whether the voice is human or canine; a burst of laughter is equivalent to a playful bark. This result agrees with a study his team published last month showing that certain acoustic properties convey emotion in both human and dog sounds. The shorter the burst of a call, for example, the more positively it is perceived.