Study co-author Victoria Ratcliffe, of the School of Psychology at the University of Sussex, said in a press release that dogs are paying attention “not only to who we are and how we say things, but also to what we say.”
Ratcliffe and supervisor David Reby played recorded speech from either side of test-subject dogs, such that the sounds entered each of the dogs’ ears, with the same amplitude.
"Although we cannot say how much or in what way dogs understand information in speech from our study," Ratcliffe said, "we can say that dogs react to both verbal and speaker-related information and that these components appear to be processed in different areas of the dog's brain.”
It’s interesting to note that both dogs and humans provide exterior clues about how their brains are operating when listening to sounds.
"The input from each ear is mainly transmitted to the opposite hemisphere of the brain," Ratcliffe explained. "If one hemisphere is more specialized in processing certain information in the sound, then that information is perceived as coming from the opposite ear."
For example, if a dog turns to its left while it’s listening, that indicates the information in the sound is heard more prominently by the left ear, suggesting that the right hemisphere of the brain is more specialized in processing that kind of information.
The researchers observed general biases in the dogs' responses to particular aspects of human speech. When presented with familiar spoken commands, in which the meaningful components of words were made more obvious, dogs showed a left-hemisphere processing bias, as indicated by turning to the right. When the intonation or speaker-related vocal cues were instead exaggerated, dogs showed a significant right-hemisphere bias.
"This is particularly interesting because our results suggest that the processing of speech components in the dog's brain is divided between the two hemispheres in a way that is actually very similar to the way it is separated in the human brain," Reby said.
This is all good news for those of us who enjoy speaking to our dogs and even confiding in them. They may not get everything that’s being said, but they usually listen attentively and do their very best to figure us out.