Inside of a Dog: What Dogs See, Smell, and Know (14 page)

What, then, are dogs saying, and how are they saying it? The
what
is answered by looking at the context of making a sound. The context includes not just the sounds around it but also the means: a screamed word winds up meaning something different than one intoned with a sultry whisper. A sound a dog makes while wagging merrily means something different than the same sound delivered through bared teeth.

The meaning of an uttered sound can also be identified by looking at what those who hear it do. Although human responses to an utterance (say,
How are you?)
may range from the appropriate (
I'm well, thanks)
to the seeming non sequitur (
Yes, we
have no bananas
), there is reason to believe that dogs, and all non-human animals, respond ingenuously. In many cases, a sound will have a reliable effect on those in the vicinity: think
Fire!
or
Free money!

The
how
of sound signaling is simple with dogs. Most of the sounds dogs make are oral: using or coming out of the mouth. At least, these are the sounds that we know about. These vocal sounds might be voiced, with vibration in the larynx—the airway used for breathing—or may be expiratory—part of an exhalation. Others are entirely unvoiced but use the mouth, such as the mechanical sound of tooth-snapping. Vocal sounds vary from one another along four easily audible dimensions. They vary in pitch (frequency): whines are nearly always high-pitched, while growls are low-pitched. Try and squeal out a growl and it becomes something else. They vary in duration: some are uttered once, quickly, lasting less than half a second; others are protracted sounds or are repeated again and again. Sounds vary in their shape: some are pure tones while others are more fractured, fluctuating or rising and falling. A howl has little variation for long periods, while barks are noisy, changeable sounds. Finally, they vary in loudness or intensity. Moans don't come in loud and yelps don't come in a whisper.

She sees I'm almost ready. With her head fixed on the ground between her paws, Pump follows me with her eyes as I cross the room gathering my bag, a book, my keys. I scratch her around her ears in consolation and break for the door. She lifts her head and makes a sound: a plaintive yelp. I freeze. A look back and she hurries over, wagging. Okay, then; I guess she'll come with me.

The paradigmatic dog sound is the bark, but barks do not form the preponderance of most dogs' daily noisemaking, which includes high and low sounds, incidental sounds, even howls and chuckles. High-frequency sounds—cries, squeals, whines, whimpers, yelps, and screams—occur when the dog is in sudden pain or needs attention. These are some of the first sounds a puppy will make, which clues us in to their meaning: they tend to attract attention of the mother. A
yelp
might come out of a puppy who was just stepped on, or who has wandered off. Deaf and blind, it is easier for mom to find her pup than vice versa. Having been reunited, some continue to yelp, winding down off their crying jag, when carried by their mothers. Yelps are different than
screams,
which in wolves prompt the mother to groom the pup, providing the contact that is necessary for normal development.
Cries
and
squeals
may be ignored by the mother, and so a particular squeal may be a less specifically meaningful utterance and instead a general-purpose sound used simply to see how others respond.

Low
moans
or
grunts
are also very common in puppies, and seem not to be signs of pain but rather a kind of dog purr. There are snuffling moans and sighing moans—what some call "contentment grunts," and they all seem to mean about the same thing. Pups moan when they are in close contact with littermates, their mother, or a well-known human caretaker. The sound might be simply a result of heavy, slow breathing, which indicates it might not be intentionally produced: there is no evidence that dogs moan on purpose (neither is there evidence that they do not; neither has been proven). But whether they do or not, moans probably function to affirm the bond between family members, whether heard as a low vibration or felt through skin-to-skin contact.

The rumble of a
growl
and the steady ominous
snarl,
you won't need to be told, are aggressive sounds. Puppies do not tend to produce them, as puppies do not tend to initiate aggression. Part of what makes them aggressive is their low pitch: they are the kind of sounds that would come out of a large animal, rather than the high-pitched squeals of a small one. In an antagonistic (what in biology is called
agonistic)
encounter with another animal, a dog wants to appear to be the bigger, more powerful creature—so he makes a big-dog sound. By making higher-pitched sounds, an animal sounds, simply, smaller: a friendly or appeasing noise, by contrast. Though aggressive in intent, growls are still
social
sounds, not just utterances produced when a dog feels fear or anger: for the most part, dogs do not growl at inanimate objects,* or even at animate objects that aren't faced or directed toward them. They are also subtler than we think: distinct growls, from rumble to nearly roaring, are used in different contexts. The growl of tug-of-war may sound fearsome, but it is nothing like the possessive warning snarled over a treasured bone. Play these growls back over a speaker set up right in front of a desirable bone and dogs in the vicinity will avoid the bone—even with no dog in sight. But if the speaker growls only play or stranger growls, nearby dogs go ahead and grab the unguarded bone.

Incidental sounds of dogs are sometimes produced so reliably in certain contexts that they have become effectively communicative. The
play slap,
an audible landing on the two forefeet at once, is an inevitable part of play. It conveys sufficient exuberance that it can be used by itself to ask a dog to play with you. Some dogs
chatter
their teeth in anxious excitement, and the clicking of teeth serves as a warning that the dog is wary. An exaggerated
shriek
on being nosed or bitten roughly in play can even become a ritualized deception, a way to get out of a social interaction that is making the dog uncertain. The
snuffling
sound created when reaching the head vertically up and sniffing for food around a human mouth can become not just a search for food but also a request for food. Even the noisy breathing created by lying so close as to have the nose pressed against another body comes to indicate a state of contented relaxation.

If you live with a hound, you are familiar with the
howl.
From a staccato baying to a mournful wail, howling in dogs seems to be a behavior left over from their ancestors, living in social packs. Wolves howl when separated from the group, and also when setting out with the group for a hunt or in reunion afterward. A howl when alone is a communication seeking company; howling together may be simply a rallying cry or celebration of the group. It has a contagious component, leading others in the vicinity to pick it up in an impromptu fugue. We do not know what they are saying, to each other or to the moon.

The most social of human sounds is the cackling laugh rumbling across the room. Do dogs laugh? Well, only when something is terrific fun. Yes, dogs have what has been called a laugh. It is not identical to human laughter, the spontaneous sounds spit out in response to something funny, surprising, or even frightening. Nor is it as variable as the cackles, giggles, and twitters that we produce. The dog laugh is a breathy exhalation that sounds like an excited burst of panting. We could call it
social
panting:
it is a pant only heard when dogs are playing or trying to get someone to play with them. Dogs don't seem to laugh to themselves, off sitting in the corner of the room, recollecting how that tawny dog in the park outsmarted her human this morning. Instead, dogs laugh when interacting socially. If you have played with your dog, you have probably heard it. In fact, doing your own social panting toward a dog is one of the most effective ways to elicit play.

Just as our laughs are often inadvertent, reflexive responses, so may dog laughs be: simply the kind of panting that results when you're throwing your body around in play. Though it might not be under the control of the dog, social panting does seem to be a sign of enjoyment. And it may induce enjoyment—or at least alleviate stress—in others: playing a recording of the sounds of dog laughter at animal shelters has been found to reduce barking, pacing, and other signs of stress in the dogs housed there. Whether mirth feels like what it does in humans is yet to be studied.

I can remember the first time a bark came out of Pump, when she was maybe three years old. She'd been so quiet until then, and then one day, after spending time with her barky German shepherd friend, a bark popped out of her. It was bark
like
more than a bark, as though a sound that stood for a bark but wasn't itself the real thing: a well-articulated
rurph!
accompanied by a little leap off her front legs and a madly wagging tail. She refined this splendid display somewhat through the years, but it always felt like a new dog thing she was trying on.

Researchers might not call barks "annoying," but they call them "chaotic" and "noisy." "Chaotic" is a good description for the variability in the kinds of sounds within each bark; "noisy" means not just
disagreeably
loud
but also
having
fluctuations
in
its
structure.
Barks are loud, and different barks have varying numbers of harmonic components, depending on the context in which the bark is used.

Still, of the sounds dogs make, barks come closest to speech sounds. The dog's bark is, like the phonemes of speech, produced by vibrations in the vocal folds and air flowing along the folds and through the mouth cavity. Perhaps because they are in overlapping frequencies—from 10 hertz to 2 kilohertz—with the sounds of speech, we are inclined to look for speechlike meaning in them. We even name the bark using phonemes from our language: the dog "woofs," "rufs," "arfs," or (although no dog I know says it) "bow-wows." The French hear the dog "ouah-ouah"; Norwegian dogs
voff-voff;
Italian dogs go
bau-bau.

Some ethologists think that barking is not fundamentally communicating anything, though: that it is "ambiguous" and "meaningless." This view is encouraged by the difficulty of deciphering what the meaning of the barks could be, since sometimes dogs bark without an obvious prompt or audience, or continue to bark long after any message therein would have been conveyed. Think of the dog barking continuously, dozens of times in a row, in front of another dog: If there is meaning in that bark, would not one or two repetitions do to convey it?

This strikes at the heart of the trouble in determining the subjective experience of an animal of which you cannot ask questions. Each moment of an animal's behavior is scrutinized for its meaning. Surely few human actions could bear such scrutiny and yield a correct assessment of the human. If you were to videotape me practicing, at home in front of my dog, a speech I am to deliver later in the day, you might well conclude that (a) I believe the dog can understand what I'm saying, or

(b) I am talking to myself. In either case, (c) holds: the noises I am making appear not to be classically communicative—for I do not have an audience who can understand me. Similarly, examples of poor communication by a dog may seem to undermine the notion that dogs communicate at all. But most researchers think that barks do have meaning, albeit one dependent on the context and even on the individual. Barking, especially alarm barking, is one of the clearest distinctions between dogs and other canid species. Wolves bark to convey alarm, but rarely, and they make more of a "woof" sound than anything like the protracted dog barking with which we are familiar. Dogs do not just bark more than wolves; they have developed numerous variations on the theme.