The researchers played the sing-song voice to a group of puppies, and they went crazy.
According to the study, the puppies barked, ran toward the speaker, and crouched down as if they were ready to play. When they heard the women reading in a more “normal” tone (aka, the tone they used to talk to other humans), they weren’t as affected. The study couldn’t definitively prove why the puppies respond better to the high-pitched, song-like speech. Their best theory is two-fold. First, they think that puppies are innately responsive to higher-pitched tones, because other dogs also use those kinds of tones to communicate. Secondly, they think that responding to baby talk from humans has been learned, because humans tend to select dogs that respond to them.