Dogs able to distinguish tone of voice, study says

To a dog, hearing an upbeat “Good boy!” versus a neutrally toned “Good boy” are distinct understandings. According to a new study, dogs are able to distinguish both vocabulary words and intonation of human speech.

Using functional magnetic resonance imaging to analyze dogs’ brain activity, researchers at Eotvos Lorand University in Budapest observed that the animals process vocabulary in a similar way to humans, using the left side of the brain, Science Daily reported. The dogs were exposed to multiple combinations of vocabulary and intonation, including praise words with a praising intonation, praise words with a neutral intonation and neutral words with a neutral intonation.

Dogs also process intonation separately from vocabulary— like humans— in the auditory regions in the right hemisphere of the brain.

Researchers found that dogs rely both on word meaning and intonation to process the reward value of phrases. By monitoring the reward regions of the brain, study authors learned that dogs respond best when praising words were used in combination with a praising intonation.

"This shows… that dogs not only separate what we say from how we say it, but also that they can combine the two for a correct interpretation of what those words really meant," lead study author Attila Andics said in a news release.

Researchers suggested than an ancient brain function exists in both humans and dogs that links arbitrary sound sequences to meanings.

The study will be published in the September 2 issue of Science.