Why do puppies like it when we use babytalk?

Many people speak to their pets – consciously or not – differently than they would with their fellow humans. A new study now provides evidence that puppies, in particular, respond well to "babytalk" and process it in their brains.

"Who's a good dog? Yes, you are... Yes, you!" – Many puppy owners often make statements like these and may not even realize in the moment that they have changed their speech melody and manner of speaking when addressing their four-legged friend. For many, this modulation of their speech happens almost reflexively and seemingly without reason. As a result, people speak to their pets like they do with toddlers. A new study now shows that puppies and dogs in general respond particularly well to "babytalk."

In any form of communication, there is a speaker and a recipient. To communicate effectively, speakers adjust to the recipient's situation. Therefore, people speak differently to friends than they do to their teachers, for example. Consequently, speakers also change their speech melody.

People tend to speak more clearly and simply to children and puppies than they would when speaking to adults. The so-called prosody (speech melody) changes. In particular, women emphasize vowels when speaking to dogs and children because their voices are anatomically very flexible. In speech directed at recipients who do not (yet) understand words particularly well, word melody also becomes clearer and varies in pitch.

Scientists from the Hungarian Eötvös Loránd University in Budapest wanted to investigate these connections and found out how dogs process words directed at them in their brains. The team led by first authors Anna Gergely and Anna Gábor published their work in the journal "Communications Biology."

It has already been proven that when speaking to toddlers, speaking loudly, overly clearly, and emphasizing vowels leads to faster learning, and toddlers recognize that they are being addressed.

To find out if the same mechanism underlies communication with dogs, the Hungarian scientists trained 19 animals of different breeds for MRI examinations. The dogs were played various speech samples from different speakers. They remained calm during the examination and could leave at any time if they wished. The speakers were not known to the dogs and used three different modes of speech. Firstly, they addressed an adult, then a toddler with a limited vocabulary, and finally, a dog.

In the experiment, the scientists were able to demonstrate that dogs responded most to words directed towards small children aged 4 to 13 months and to speech directed at them. They also did not differentiate between the speech patterns, highlighting a similarity between both forms of communication. Notably, female voices led to strong neural reactions. Previously, this reaction had been explained in cognitive linguistics by the fact that children become most accustomed to their mother's voice even before birth. 

However, this study with dogs, who cannot hear until the third week of their lives and belong to a different species, provides insight into the likelihood that this is probably not the main reason. The scientists propose two explanations for how such gender- and recipient-dependent prosody sensitivity could have evolved in the canine brain.

Firstly, it could be attributed to an ancient and universal sensitivity in the animal kingdom, linked to a heightened awareness of higher tones and changes in speech. This typically occurs in more excited forms of communication. Secondly, this response could also be specific to animals living in human-influenced environments and evolving there. In such environments, this language becomes part of their natural sensory stimuli. Additionally, higher-pitched voices may more easily capture and maintain the attention of animals. Furthermore, the neural sensitivity to dog-directed speech develops over the course of the animals' lives through positive reinforcement.

These findings provide insights into the influence of domestication and the animals' ability to comprehend verbal commands.