In 1999, journalist, author, and novelist John Colapinto damaged his vocal cords while singing in a rock band without properly warming up. The incident sparked a decades-long investigation into the miracle of the human voice and its biological, sociological, and psychological implications.

Colapinto poured his research—which began with an article he wrote for The New Yorker, where he’s a staff writer, about vocal surgeon Steven Zeitels, who has worked with Steven Tyler, Cher, and Adele—into his book, This Is the Voice (Simon & Schuster), out this month in paperback, which tells the story of the human voice from its ancestral precursors in lungfish millions of years ago to its role as a powerful, efficient tool wielded by most people every day. He also explains how the voice can provide clues about a person’s age, sexual preference, and culture, and argues that humans’ physiological adaptations that developed to enable speech some 50,000 years ago are the evolutionary key that led to our role as earth’s dominant species.

Here, Colapinto talks about the voice as “acoustical lasagna,” and how it subconsciously informs our social interactions and tells people how we truly feel, even if that’s at odds with what we’re saying.

“The voice is the unifying thing that is of relevance to humans as a species. It’s how we collaborated and conspired against tougher, bigger, faster, more lethal animals. Noam Chomsky, other linguistics experts, and every evolutionary biologist you can think of will say that we rose to the top of the food chain because of language, because that’s the way that we organize ideas in our brains. But more specifically, we do it with our voices. And we were able to speak only because of highly specific evolutionary anatomical changes to our vocal apparatuses.

The development of those apparatuses fascinates me. Our voices come from an ancient lungfish, which was the first creature to emerge from oceans, where life began as single-cell organisms. It was through a refinement of the breathing apparatuses of these fish, which were eventually both land-dwellers and water-dwellers, that our vocal cords emerged. Our vocal cords are not like guitar strings, but are instead valves that we open and close when we want to speak, a coordinated system of throat buzzes and movement of tongue and lips. Every day we beam ideas into each other’s heads by making air molecules vibrate in particular ways.

Sometimes I talk about the voice as an ‘acoustical lasagna,’ because there are so many different layers of communication. One thing we pick up from someone’s voice is a linguistic layer: We hear a very precise and elegant vocabulary and think that that person might have gone to a fancy school, or has done a lot of reading. But we’re also getting a tremendous amount of information from the accent, the way people shape consonants and vowels. When we hear Bernie Sanders talk, we’re hearing that he says ‘New York’ and ‘car’ a particular way. He doesn’t include the ‘R’ sound. We know that that’s true of Woody Allen as well. All of this tells us that both of those guys come from Brooklyn, or the outer boroughs of Manhattan, from pretty early in the twentieth century. If you hear a voice that is pressurized and fast, a little on the edge, and jumping on the consonants, it may signify anger, or that someone is pent up. A voice like that of Donald Trump, another person from New York and in his seventies, sounds very combative.

There’s also the emotional channel of the voice. We’re communicating literally how we feel—hostile, afraid, excited, happy. Many fine gradations of emotion occur within the vocal channel that can be totally different from what we’re saying. People can pick up lies in voices, for example. In his books On the Origin of Species and The Descent of Man, Charles Darwin talks about how this emotional signaling through voice emerges from animal voices. We see this in a dog that makes a low-pitched growling sound to suggest that it’s angry, or a high-pitched whining sound to signal that it’s submissive. Every animal on earth that has a voice uses exactly the same spectrum of sounds. Most people don’t know it, but if you intimidate certain birds, they respond in a low voice. Then they’ve got their high-pitched singing voice that demonstrates happiness. Cats do the same thing.

This is a type of signaling. What is it all about? A low-pitched sound suggests a big body—think of a cello versus a violin. It suggests a big resonating chamber. So it’s a bluffing sound. It’s literally an evolutionary adaptation in a threatening situation, to pretend you’ve got a bigger body. Even mice do this. When they’re threatened, their voice lowers, and when they’re trying to mate and elicit attraction, their voices go higher. I love that—and, like them, we’re doing the same thing, all the time.”