An important and inconvenient question: What are these tests actually measuring? Behind the highbrow theory and ground-level research, what does Beyond Verbal's diagnosis actually mean? Emodi will tell you it comes down to brute biology. He traces the vocal inflections to changes in the limbic system, the physical equivalent of the sensations we know as emotion. On the theory side, Plutchik goes even deeper, tracing the component emotions to human reactions to the basic problems of life, like identity, hierarchy, and temporality. We feel joy in gaining something, and sadness in losing it; as long as human beings are gaining and losing, Plutchik tells us we will feel something akin to joy and sadness. It’s a powerful idea, especially when it’s combined with data-driven voice analysis. Following the assumptions of Plutchik and Beyond Verbal, you can trace the thread of a vocal tic all the way back to the elemental struggles of human existence.

There's a rush that comes with putting a word to another person's emotional state

But from another angle, that tic could mean nothing at all. Plutchik has a good theory but it's just a theory, and it's not the only one. As critics point out, his theory doesn't have much to say about emotions like pride or shame. Beyond Verbal had help from results on the ground: they really did see improved performance at the call centers. But why? Had they tapped into the basic emotions of the callers, or did they just train the operators to respond more effectively? Is Moodies scanning for emotion, or just measuring and cataloging the quirks of a person's voice? Can the two be separated at all? They're hard questions to dismiss entirely, especially as emotion sensors like Beyond Verbal make their play for top-dollar acquisitions. Taking a stand on emotional intelligence also means taking a stand on the nature of emotion itself, which can make for shaky ground.

At the same time, the trick itself isn't getting old. There's a rush that comes with putting a word to another person's emotional state, perhaps knowing more about them than they know themselves. "You can see all the emotion, you can follow it from one emotion to another," Emodi says. "You can take that into cars, TVs, and smart appliances." After years of trying out the tech, he's addicted. He uses it to practice pitches, screen potential hires, and monitor his tone when he needs to scold his kids. And why wouldn't you? For Emodi, it's the best kind of information there is. "We say what we want to say, but what's really important is how we feel."