Inasmuch as we are a purebred dog-centric site, there are the occasional posts that apply to all dogs regardless of ancestry, and we share them because they’re interesting!
Play along with us for a minute. There are two sound bars below. Click on the arrow of the first one to hear the track and picture the dog in your mind as you hear this canine bark:
Now do the same thing to this track:
We’re pretty sure that most of you visualized a small dog with the first track, and a much larger dog with the second – but do you know why their barks are different?
And yes, it has to do with size, but we’re not letting you off that easy. Can you explain why, exactly, a dog’s size impacts the pitch of its bark?
It’s more complex than you might first think.
The difference in barks as it pertains to size is largely due to the size of a dog’s vocal cords, the overall shape of its larynx, and its resonating chambers. Large dogs have longer and thicker vocal cords which vibrate at a lower frequency, and thus produce deeper sounds. Small dogs have shorter, thinner vocal cords that vibrate at a higher frequency, and those result in higher-pitched barks. The length of a dog’s vocal tract is also directly correlated with body size. Big dogs have longer vocal tracts which lowers the formant frequencies of their vocalizations and contribute to a deeper bark. Smaller dogs have shorter vocal tracts which produce higher formant frequencies and those lead to higher-pitched barks.
Meanwhile, the dog’s larynx, or voice box, is proportionally larger in big dogs. Larger space allows for more air movement and contributes to the deeper, more resonant sound of a big dog’s bark. Since the chest cavity, throat, and mouth act as resonating chambers for a dog’s bark, big dogs have big resonating chambers which amplify lower frequencies and contribute to a fuller, deeper WOOF. Big dogs also tend to have larger lungs which literally allow them to push more air through their vocal gear. Increased air volume contribute to a louder, more powerful WOOF. Did you know that the shape and size of a dog’s skull can also affect the sound of its bark by influencing how sound waves are shaped and projected?
All these anatomical differences explain why a Chihuahua’s bark sounds so different from a Rottweiler’s bark even though they both use the same basic mechanisms to produce sound. But there’s one more thing that influences a dog’s bark, and we bet it’s one you don’t see coming:
A dog’s tongue can influence the sound of its bark. Its size and shape can alter the tonal quality of its bark. Dogs with a larger tongues tend to produce a deeper barks as compared to a toy breed with a smaller tongue, which results in a higher-pitched bark.
How?
A larger tongue can narrow the opening of the dog’s throat resulting in a deeper and more resonant bark. Conversely, a smaller tongue allows for a wider throat opening, leading to a higher-pitched bark. The position of the dog’s tongue within it mouth can change the acoustic properties of the bark. When the tongue is positioned closer to the roof of the mouth, for example, it can produce a more muffled sound. If the tongue is positioned lower, however, the bark can be clearer and more pronounced.
We know how annoying it is when a dog barks. And barks. And barks. But the next time your dog has a lot to say, stop for a moment and consider what is happening in that dog’s mouth. There are eight main muscles in a dog’s tongue – four “intrinsic” pairs and four “extrinsic muscles, all of them composed of multiple neuromuscular compartments or fascicles, which allows for complex movements and shape changes of their tongue. These muscles allow the tongue to move in complex ways by adjusting the shape and size of the oral cavity, which in turn affects the sound produced.
Some dog’s “arroooo, “others don’t.
Further more (and here we’re going to get all sciency on you), the dog uses her hypoglossal nerve to innervate her tongue muscles which enable precise movements. This neuromuscular coordination allows her to modify her bark by changing the tongue’s position and tension. This is pretty similar to how we humans articulate different sounds.
Image by © Anna Yordanova | Dreamstime