Researchers have found evidence that the high-pitched baby talk we use to interact with our dogs is largely ignored by our older pooches, though puppies seem to enjoy it.

The study looked into how humans most commonly communicate with their dogs, and showed that not only is baby talk pretty cringeworthy to watch, it's also wasted on grown-up dogs who pay it no attention.

The scientific term for baby talk is 'infant-directed speech', and it's basically the term given to any time we talk to a baby in a higher-pitched, simplistic form of language full of nonsense words and noises.

While this type of speech seems pretty nonsensical, scientists have found that infant-directed speech plays a big role in early childhood development.

As the team, led by Nicolas Mathevon, from City University of New York, explains:

"This infant-directed speech has positive aspects in engaging and maintaining attention of babies and facilitating their social interactions with caregivers: infants as young as seven weeks old show a preference for infant-directed speech over adult-directed speech.

Accordingly, infant-directed speech has been shown to increase cerebral activity more than adult-directed speech, meaning that infants are more engaged in what is being said to them when they listen to this special speech register."

The strange thing is, we also use this same type of speech to communicate with our pets - especially dogs - which the researchers refer to as 'pet-directed speech'.

But very little research has been done into why we do this, and whether dogs actually respond to it or not.

"Although dogs clearly do not possess the language ability, humans do change their speech patterns when talking to dogs using what is known as pet-directed speech, which shares similar structural properties with infant-directed speech (e.g. high-pitch register, slower tempo)," the team writes.

So does this type of speech do anything for our beloved dogs, or is it just a leftover human behaviour that we use on them out of habit or love?

To find out, Mathevon and his colleagues devised an experiment involving 30 women who were asked to look at 90 different dog photographs. Thirty of the dogs in the photos were puppies, 30 were middle-aged, and 30 were old.

They then asked the women to say common dog phrases while looking at the pictures.

Things like "Good boy", "Cutie pie", and "Whooza good boy? You are! You are!" were directed at the pictures to see how the volunteer's voices changed when talking to dogs of various groups, and to see if their voices rose in pitch that's similar to infant-directed speech.

For each participant, they made a set of four recordings: puppy-directed; adult dog-directed; old dog-directed; and adult human-directed as the control. They each had identical verbal content.

The team found that the women tended to talk to dogs of all ages in high-pitched dog-directed speech – very similar to baby talk – but their voices got slightly more higher-pitched when speaking to puppies rather than older dogs.

They then took the puppy- and adult dog-directed recordings and played them back to 40 different dogs of various ages before or after human-directed recordings, to see if the dogs responded more or less to the dog-directed baby talk compared to the human-directed talk.

Playing the voices back instead of having the volunteers work directly with the dogs helped narrow down the variables, so they wouldn't be distracted by body language or familiarity with the volunteers.

As for the dogs, puppies paid more attention to the speaker whenever dog-directed speech was played back rather than human-directed speech – regardless of whether the recordings were made to adult dogs or puppies. 

Dogs of other ages listened to the playbacks, but they weren't any more interested in the dog-directed talk than the human-directed talk. Which suggests they didn't respond to the baby talk we use on dogs.

These findings suggest that humans use dog-directed speech all the time, but even though it influences puppies, it has no impact on adult dogs like it does with young children.

Instead, the team thinks that we use this type of speech when talking to a listener that cannot communicate back, such as babies, dogs, and cats.

"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," Mathevon told George Dvorsky at Gizmodo

"This study does not tell much about dogs, but more about our human behaviour."

This isn't the only human behaviour that is lost on our pets - back in 2016, researchers from Canada found that most dogs get pretty uncomfortable when you hug them, expressing clear signs of stress.

But good news is that not all dogs feel that way, and you can tell by looking for the signs.

Will these studies stop us from babbling to our dogs or giving them big hugs?

Probably not, but know that those actions are likely more for you than they are for your dog. So be a good human and learn to read the cues given off by your dog about what it's most comfortable with.

The study was published in Proceedings of the Royal Society B.