The Outer Worlds provides tons of content for the player to enjoy, including a massive cast of characters to interact with. Throughout the journey, there are 346 characters you'll come in contact with, and each one is voiced. In an interview with GamesIndustry, Justin Bell, the in-house audio director at Obsidian Entertainment, said those voices came from just 40 actors.
"There are 346 distinct characters in The Outer Worlds. This was a fulltime undertaking, to say the least. ...We gathered character traits for all characters, like age, gender, ethnicity, archetype, world location, quest location, and we did some analysis to determine how we could cluster them together into groups that would be assigned to a single actor. After that, it became a balancing act of ensuring we had enough actor variety per group so that we didn't hear the same actor over and over again, which would be immersion-breaking for the player."
This is just one small snippet of a feature on the massive undertaking of bringing The Outer Worlds together. You can check out the full article here.