Ruth Nall is a talented talker. Always has been. When she was a child, her mother taught her to enunciate her words when she spoke, which she did often and at length. So wordy was she that, in grammar school, her friends nicknamed her "Yakky Roo," partly for her ace Yakky Doodle impersonation, but also for her loquaciousness.

I know this because Nall, who these days teaches high school kids, told me so, in a pleasantly wide-ranging conversation about her participation in a study led by UCSF Health neurosurgeon Edward Chang. Some years back, Nall was diagnosed with epilepsy, which landed her in Chang's charge. To find where her seizures were originating, Nall had an array of tiny electrodes placed directly on the surface of her brain. Around the same time, Chang, who is also a researcher at UC San Francisco, was trying to identify the area of the human brain responsible for controlling pitch.

Pitch is an important part of conveying information through speech; the subtext of the phrase "I love you" varies according to whether you emphasize the first, second, or third word. Chang wanted to see whether he could isolate the region of the brain responsible for imparting our speech with these nuances of prosody.

But there was a hitch: To do it, Chang would need to take high-resolution readings of electrical activity from inside his test subjects' skulls. This research method, called electrocorticography, or ECoG, requires major surgery, which is why it almost never happens without the voluntary participation of patients who have electrodes on their brains for therapeutic reasons. Fortunately for Chang, Nall, with her ample appreciation for the spoken word, was just the person to ask.

"I said, wow, of course. Because verbal communication with people is so crucial. The technologies we have—with our texting and our email—they're great, but nothing beats a conversation with somebody," Nall says. "The things you hear—the tone, the emphasis, the feeling—are what convey the information behind the words. It's like I tell my students: It's not just what you say, it's how you say it."

Physiologically, pitch is controlled by the larynx, a hollow hunk of multitalented muscle perched at the top of your neck. It's involved in everything from breathing to choking-prevention. Commonly known as the voice box, it also houses your vocal cords. The muscles of the larynx generate sound by bringing those cords together, and modifies the pitch of that sound by varying their tension.

Animation by Dichter et al.

Just as the larynx controls the vocal cords, the brain controls the larynx. That's where ECoG comes into play. To study the brain-larynx link, Chang recruited Nall and 11 other patients with epilepsy who already had electrode arrays implanted inside their skulls. The results of the investigation, which appear in the latest issue of Cell, uncover the region of the brain that controls the vocal folds of the larynx, and point the way towards speech prosthetics that could allow people unable to speak to express themselves in more natural, nuanced ways.