The tongue and its taste buds give us just the basic textures and attributes of food—whether they are soft or smooth, sweet or bitter, and so on—but the full sensuousness of it all is dependent on our other senses. It is nearly always wrong to talk about how food tastes, though of course we all do. What we appreciate when we eat is flavor, which is taste plus smell.*3
Smell is said to account for at least 70 percent of flavor, and maybe even as much as 90 percent. We appreciate this intuitively without often thinking about it. If someone hands you a pot of yogurt and says, “Is this strawberry?” your response will normally be to sniff it, not taste it. That is because strawberry is actually a smell, perceived nasally, not a taste in the mouth.
When you eat, most of the aroma reaches you not through your nostrils but by the back staircase of your nasal passage, what is known as the retronasal route, as opposed to the orthonasal route up your nose. An easy way to experience the limitations of your taste buds is to close your eyes, pinch shut your nostrils, and eat a flavored jelly bean collected blindly from a bowl. You will instantly apprehend its sweetness, but you almost certainly won’t be able to identify its flavor. But open your eyes and nostrils and its fruity specificity becomes immediately and redolently apparent. Even sound materially influences how delicious we find food. People who are played a range of crunching sounds through headphones while sampling potato chips from various bowls will always rate the crunchier, noisier chips as fresher and tastier, even though all the chips are the same.
Many tests have been done to demonstrate how easily we are fooled with respect to flavor. In a blind taste test at the University of Bordeaux, students in the faculty of enology were given two glasses of wine, one red and one white. The wines were actually identical except that one had been made a rich red with an odorless and flavorless additive. The students without exception listed entirely different qualities for the two wines. That wasn’t because they were inexperienced or naive. It was because their sight led them to have entirely different expectations, and this powerfully influenced what they sensed when they took a sip from either glass. In exactly the same way, if an orange-flavored drink is colored red, you cannot help but taste it as cherry.
The fact is that odors and flavors are created entirely inside our heads. Think of something delicious—a moist, gooey, warm chocolate brownie fresh from the oven, say. Take a bite and savor the velvety smoothness, the rich heady waft of chocolate that fills your head. Now consider the fact that none of those flavors or aromas actually exist. All that is really going in your mouth is texture and chemicals. It is your brain that reads these scentless, flavorless molecules and vivifies them for your pleasure. Your brownie is sheet music. It is your brain that makes it a symphony.
As with so much else, you experience the world that your brain allows you to experience.
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There is of course one other remarkable thing we do with our mouths and throats, and that is make meaningful noises. The ability to create and share complex sounds is one of the great wonders of human existence and the characteristic more than any other that sets us apart from all other creatures that have ever lived.
Speech and its evolution “are perhaps more extensively debated than any other topic in human evolution,” in the words of Daniel Lieberman. No one knows even approximately when speech began on Earth and whether it is an accomplishment confined to Homo sapiens or whether it was a skill mastered by archaic humans like Neanderthals and Homo erectus. Lieberman thinks it likely that Neanderthals commanded complex speech based on their large brains and array of tools, but it isn’t a provable hypothesis.
What is certain is that the capacity for speech requires a delicate and coordinated balance of tiny muscles, ligaments, bones, and cartilage of exactly the right length, tautness, and positioning in order to expel microbursts of modulated air in just the right measures. The tongue, teeth, and lips must also be nimble enough to take these throaty breezes and turn them into nuanced phonemes. And all of this must be achieved without compromising our ability to swallow or breathe. That’s quite a tall order, to put it mildly. It isn’t just a big brain that allows us to speak but an exquisite arrangement of anatomy. One reason chimps can’t talk is that they appear to lack the ability to make subtle shapes with tongue and lips to form complex sounds.
It may be that all this happened fortuitously in the course of an evolutionary redesign of our upper bodies to accommodate our new posture when we became bipedal, or it may be that some of these features were selected for through the slow, incremental wisdom of evolution, but the bottom line is that we ended up with brains big enough to handle complex thoughts and vocal tracts uniquely able to articulate them.
The larynx is essentially a box about an inch on each side. Within or around it are nine cartilages, six muscles, and a suite of ligaments, including two commonly known as the vocal cords but more properly known as the vocal folds. When air is forced through them, the vocal folds snap and flutter (like flags in a stiff breeze, it has been said), producing a variety of sounds, which are refined by tongue, teeth, and lips working together into the wondrous, resonant, informative exhalations known as speech. The three phases of the process are respiration, phonation, and articulation. Respiration is simply the pushing of air past the vocal ligaments; phonation is the process of turning that air into sound; and articulation is the refinement of sound into speech. If you wish to appreciate what a marvel speech is, try singing a song—“Frère Jacques” serves very well—and notice how effortlessly melodic the human voice is. The fact is, your throat is a musical instrument as well as a sluice and wind tunnel.*4
When you consider the complexity, it is hardly surprising that some people struggle to put it all together. Stuttering is one of the cruelest and least understood of everyday maladies. It affects 1 percent of adults and 4 percent of children. For reasons unknown, 80 percent of sufferers are male. The victims have included a great many distinguished figures—Aristotle, Virgil, Charles Darwin, Lewis Carroll, Winston Churchill (when young), Henry James, John Updike, Marilyn Monroe, and King George VI of Great Britain, who was sympathetically portrayed by Colin Firth in the 2010 movie The King’s Speech.
No one knows what provokes it or why different sufferers stumble over different letters or words in different positions in a sentence. It is more common among left-handers than right-handers, especially those who have been made to write right-handed. For many, the stammering miraculously ceases when they sing the words or speak another language or talk to themselves. The majority of speakers recover from the condition by their teenage years (which is why the proportion of child sufferers is so much higher than adult ones). Females seem to recover more easily than males.
There is no reliable cure for stuttering. Johann Dieffenbach, one of Germany’s most eminent surgeons in the nineteenth century, thought stuttering was entirely a muscular complaint and believed he could cure it by cutting out some of his patients’ tongue muscles. Although the process was wholly ineffectual, it was widely copied throughout Europe and the United States for a while. Many patients died; all suffered mightily. Today, mercifully, most sufferers are helped significantly with speech therapy and a patient, compassionate approach.