A new study found that dogs pay attention to human words and understand the emotions behind it. The finding is the first evidence that man's bestfriend can distinguish and react to human speech.

Researchers from the School of Psychology at the University of Sussex observed 250 dogs of different breeds in a laboratory. They were all placed in a room with speakers on their heads. The speakers were activated separately to discern how the dogs will react when the sound comes to the left and right side of their head.

The dogs heard various sounds such as "Come on, then!" with no emotion. The same phrase was also distorted and changed to have different intonation and different emotions. The researchers observed that when the words don't have emotions, the dogs turned their heads to the right side, and the other way when emotions were added. They also observed that dogs do not respond to distorted sounds, according to LiveScience.

The experiment showed that the sounds played on the right ear of the dogs are being processed by the left hemisphere of the brain, and vice versa.

Earlier studies found that dogs react to the vocalization of other dogs, and the finding of the study suggests that this bias is observed when it comes to human words. But the researchers clarified that their research does not mean that dogs understand everything we say, but rather that they pay attention to what we say.

"Although we cannot say how much or in what way dogs understand information in speech from our study, 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," said study author Victoria Ratcliffe of the School of Psychology at the University of Sussex in a press release.

This study was published in the Nov. 26 issue of Current Biology.