I’ve used online text-to-speech programs to create the voices, and those have been around for a long time the first ones go back to the 1960s. But I know what you’re talking about, in recent years, AI voice cloning has become popular. It uses existing recordings of a person’s voice to generate new speech that sounds just like them, so you can make that voice say almost anything, it pretty cool and super funny like making mr beast say anything you want.