According to a recent study published in the journal Science, the answer is yes! Researchers were aiming to investigate how dogs process words and intonations in human speech. They found that dogs' brains process words themselves with the left hemisphere, while the right hemisphere processes tone of voice. This is very interesting, considering that human brains process speech in the same way!
Even more fascinating is the finding that dogs use their ability to separately process words and tone of voice to better understand the meaning behind what we say to them. Dogs in the study only considered speech to be "praise" if both words and tone of voice were positive. If nonsense words were spoken in a pleasant voice, or if words they recognized were spoken in a monotone manner, dogs did not consider the speech to be "praise." The dogs only found the speech to be rewarding when both the tone of voice and the words spoken matched up.
This very cool, insightful study gives dog owners and trainers a good reason to pay attention to how we speak to our dogs; clearly, they're paying attention too!