You can't help it. You see that sweet little face and immediately begin to blabber in a sing-song voice, "Hello, sweetie pie! Who's a good boy?!"

We tend to talk to puppies as we do to babies, speaking slowly in a high-pitched voice. An international team of researchers recently looked at the science behind what they call "dog-directed speech" to find out why we do it and if our canine friends truly respond to it.

When we talk to babies, we speak more slowly, using a higher and more variable pitch, the researchers say. We also tend to articulate our vowels more clearly than when we're talking to adults. This "infant-directed speech" engages and maintains the attention of babies as young as 7 weeks old, who prefer it over normal adult speech. Researchers decided to apply the same rules to dogs.

The 'sweetie pie' experiment

For the first part of the experiment, people were asked to say the phrase, "Hi! Hello cutie! Who's a good boy? Come here! Good boy! Yes! Come here sweetie pie! What a good boy!" while looking at photos of puppies, adult dogs, older dogs and then while looking at no photos. The researchers then analyzed the recordings to see how speech patterns changed while people were speaking to different aged dogs.

They found that the volunteers used higher-pitched, slower-tempo speech with the pitch varying when talking to the dogs. The most obvious change was with puppies, when the volunteers increased their pitch by 21 percent on average compared to normal speech. (Their pitch increased on average by 11 percent when they spoke to adult dogs and 13 percent with old dogs.)

The results, which involved researchers from the U.S., the U.K. and France, were published in the journal Proceedings of the Royal Society B.

Puppies like 'puppy talk'

little boy talking to puppy Puppies are more reactive to dog-directed speech, and their response to the higher pitch is a key reason why. (Photo: Golden Pixels LLC/Shutterstock)

For the second part of the experiment, the recordings were played for puppies and adult dogs. The researchers found that the puppies responded more strongly to the dog-directed recordings than the adult dogs. For example, they reacted more quickly to those recordings, looking more frequently at the speaker and approaching it closer and for longer periods of time. Adult dogs in the experiment didn't seem to have a preference how people spoke to them.

"One of the hypotheses was that we humans use this dog-directed speech because we are sensitive to the baby cues that come from the face of a small baby [animal] as we are sensitive to the faces of our babies," study co-author, psychology professor Nicolas Mathevon of the University of Lyon/Saint-Etienne, told BBC News.

"But actually our study demonstrates that we use pet-directed speech or infant-directed speech not only because of that, but maybe we use this kind of speech pattern when we want to engage and interact with a non-speaking listener. Maybe this speaking strategy is used in any context when we feel that the listener may not fully master the language or has difficulty to understand us."

Mary Jo DiLonardo writes about everything from health to parenting — and anything that helps explain why her dog does what he does.