We often speak to dogs, regardless of their age, in a sweet, high-pitched and nonsensical manner, much in the way we express ourselves to babies. Why is this? Well, a new study has shown that puppies become not only more excited but also more receptive to our pooch-directed speech. It appears that younger dogs directly respond to this way of talking, and it may even help them to learn words like human babies, suggesting that this way of talking might be our natural method of trying to interact with non-speaking listeners. Meanwhile, older dogs seem somewhat apathetic to our cooing, as they tend to develop an indifference to our vocal affection as they age.
In a study for the Proceedings of the Royal Society of Biological Sciences, Nicolas Mathevon, a bioacoustican at the University of Lyon in Saint Etienne, recorded the voices of 30 women as they looked at individual photographs of dogs. Whilst doing so they were asked to read excerpts from a script which included phrases such as “Hello cutie!”, “Who’s a good boy?” and “Come here sweetie pie!” before then repeating the same phrases to a person.
When comparing the differences between speech directed towards the images of dogs and that said towards a human-being, Mathevon and his colleagues found, as expected, that the women would immediately speak in a highly pitched and distinctive voice when confronted with a photograph of a dog, yet reverted to type when speaking to a human-being. The female participants also tended to use a similar tone of voice regardless of the age of the dog presented to them, yet tended to use a slightly higher pitch when they were talking to images of puppies.
These separate recordings were then taken to an animal shelter in New York and shown to 20 dogs (10 of which were puppies) and the responses were recorded. Of the 10 puppies involved, nine reacted strongly to the recordings by barking at the loudspeaker and in some cases bowing towards it as if inviting it to play. The puppies were distinctly less interested in the voice recordings of the women towards humans, whilst the older dogs weren't bothered at all. As Mathevon recollects, ‘they had a quick look at the speaker, and then ignored it’.
It may simply be that older dogs are more receptive to accustomed voices and their manifestation through a familiar, physical presence rather than a disembodied voice. In stark contrast the higher pitched voices seemed to create a mutually beneficial experience for both dog and human as it caught the puppies’ attention.
According to Monique Udell, an animal behaviourist at Oregon State University, the study shows that even in our speech ‘we care for and treat dogs of all ages like human infants’ declaring it an important part of the reason behind dogs evolving ‘success in human environments’. Mathevon furthers this argument and says the results show more about human behaviour than they do about dogs:
"I think that we are directing a human behaviour at dogs. Our study suggests that we use this kind of speech pattern to engage interaction with a non-speaking listener. This study does not tell much about dogs, but more about human behaviour. It underlines that we try to adapt the way we speak to our listener—or to what we think our listener is able to understand."
Further research will be required to discover whether puppies have an innate response to this so-called dog directed speech or whether it’s something they learn and acquire to aid their understanding of human speech and the emotional context with which its attached.