Chell is the protagonist in Portal series, a puzzle FPS developed by Valve Corporation. Erik Wolpaw, who wrote the dialogue for Portal and wrote Portal 2 with other people, felt that the personality of Chell wasn't really important for making Portal.
GLaDOS, the nefarious artificially intelligent operating system, is irritated by Chell's silence -- saying "Are you even listening to me?". Wheatley, another AI from Portal 2, asks Chell to jump, instead of talk, to respond his questions. As these examples suggest, characters in Portal series DO understand that Chell is a silent woman.