Our voices have superpowers. From a coach firing up a soccer team before a big game to a mother soothing a cranky baby in the middle of the night, the human voice is key to expressing feelings and forging connections. The tone of a person’s voice might even communicate feelings to loved ones better than facial expressions. So what happens to a person when their voice disappears?

People who have lost the ability to speak due to neurodegenerative disease or brain injury are talking again thanks to groundbreaking technologies that can decode the instructions the brain sends to speech muscles. For this issue’s cover story, senior neuroscience writer Laura Sanders interviewed Casey Harrell, a man who regained his voice — lost to ALS — through a brain-computer interface .

You can listen to Harrell in his own words in Season Two of The Deep End , our award-winning podcast.…