Speech-language pathologist Christina Hunger can make her dog talk—without barking. The 26-year-old has devised a way for her pup Stella to use human language to communicate her needs. Thanks to Hunger’s ingenuity, the Catahoula/Blue Heeler mix can specify when she is thirsty, when she wants to go outside, and when she is looking for her favorite toy. Hunger documents Stella’s burgeoning skills in short videos and their back-and-forth conversations are nothing short of amazing. So, how does Stella talk? Hunger created an adaptive device that features rows of large, colorful buttons. Each switch corresponds to a different word that describes...