The Evolution of Human-Dog Vocal Communication
Vocal communication between dogs and humans has evolved to be highly effective, shaped by the needs of both species.

While humans adjust their speech to accommodate dogs’ hearing capacities, dogs have developed a sensitivity to human speech cues, even without prior exposure.

Dogs’ vocalizations differ from human speech in rhythm, often operating at a slower rate. These vocal rhythms align with the dog’s neural processing, which is more tuned to lower-frequency sounds than humans.

Now, scientists have made brainwave measurements on both the dog and the humans to compare their brainwaves when communicating with each other.

The study
The study investigated auditory brain processes in dogs, comparing them to humans. They used EEG in both species to measure brain responses to speech stimuli.

Dogs were exposed to command words (e.g., "sit," "come"), while researchers observed their responses. Humans, on the other hand, listened to streams of words and gave feedback on how clear and understandable they found the speech.

It was found that both species did neural tracking of speech, with differences in the frequency bands involved: humans showed better tracking in syllables, while dogs primarily tracked in words. This suggests that humans track speech at the syllable level, while dogs focus on word-level tracking.

The research showed that as speech rate increased, both human and dog brain responses decreased, indicating that faster speech impairs comprehension.

Interestingly, the way dogs respond to human speech suggested that human vocal production has adapted to match dogs’ auditory capacities. This finding supports the hypothesis that human speech evolved to be more comprehensible to dogs, indicating a co-evolution of communication patterns.

So, how can you help your dog decode you?
Dogs’ vocal (dog-talk) rhythm is slower than humans', with their natural vocalization rate centered around 2 Hz. This slower rhythm is consistent with the vocalization system of other non-human animals.

The study proposes that this slow rhythm may be the best for human-to-dog communication, with humans adjusting speech rate to align more closely with the dog's auditory system, enhancing effective communication.

In conclusion, this study shows that dogs and humans process sound patterns differently over time, highlighting unique ways their brains handle speech and vocal cues. While both species process speech differently, humans may have adapted their speech to better align with dogs’ neural capabilities, potentially strengthening interspecies communication.

About the scientific paper:

First author: Eloïse C Déaux, Switzerland/France
Published: PLos Biology, October 2024
Link to paper: https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3002789