What do dogs really hear?

Joseba Bidaburu

What do dogs really hear?

Image yourself at Gonzaga University exiting Hughes and across Herak lawn a crowd is starting to grow, so you ask yourself what is going on. At first glance it looks like it could be a collegiate squirrel but then upon further investigation it becomes clear to you that it is a canis lupus familiaris commonly known as a dog. Upon realization you make it a goal that you will go and pet this dog, but just as you are about to get within the petting range the owner says, “Come on boy! Lets go.” Leaving you just inches away from your goal. With a minor setback in your day trotting away you stumble upon a scientific question, “Do dogs really understand human speech?”. But thanks to the scientific community and the men and woman who make it up this very question is trying to be answered. 

In a recent scientific study the question of dog-directed speech is being analyzed to determine why people use it when speaking to dogs, and if dogs pay attention to it. The first part of the study looked at how the human voice changed in harmony and pitch when looking at a dog. The second part of the study was to examine how a dog would react to the sound of a human voice. To run this test thirty women were used, they read off of a script that included phrases like, “What a good boy!” and “Come here!”. At first these were a control (human-directed speech) so no dog image was present. Then the participance were shown images of dogs and as a resource they said (dog-directed speech) the same phrases from the control. The images were divided into three categorizes puppies (less then a year old), adult dogs (1-8 years old), and old dogs (older then 8 years). Then the voices were analyzed. 

The second part of the studies was to see how dogs respond to the two types of speech; human-directed and dog-directed speech. Twenty dogs were used for the sample ten puppies and ten adult dogs. All dogs were given the same treatment, they were in a spacious room and had time to adjust so they did not feel uncomfortable in the room. Then the audio samples from the first part of the experiment were played for the dogs. The human-directed and dog-directed speech was played for thirty second intervals, with five minute breaks in between. The scientist looked at how the dog responded to the different types of speech; specifically looking at how quickly they responded and how long they showed interest after the audio stopped playing. This study was able to show that when a human is presented with the image of a dog that the voice will change, with a higher pitch and higher degree of harmony. This seems to happen because it is the natural way humans help others learn. When a human speaks to infant the same thing happens, it is a mechanism to improve linguistic performance. A similar behavior is seen when speaking to the elderly and linguistic foreigners. More evidence of this is that the dog-directed speech decreased as the dogs appeared to be older. Examine the second half of the study it was clear that puppies had a very strong response to the dog-directed speech. The adult and old dogs also responded but it was with less spontaneity and duration. This is seen in the wild with wolves because high pitched tones are associated with feeding. This study was able to show that dogs respond best to dog-directed speech also humans use dog-directed speech when a dog is present.