While he doesn't talk in the game, it's not hard to imagine that he is communicating to people (other than enemies via the communication of violence), by their reactions to Gordon.
In Black Mesa East, Alyx will look at Gordon and smirk when Gordon is being lectured to concerning the Resistance's guidelines, perhaps a quiet snarky comment Gordon gave over to Alyx. When Gordon meets Barney while in disguise, he tries to joke and comfort the possibly freaking out scientist (He had just been teleported into a fascist regime with nothing, alone and friendless, but, turns out he had several friends where he went to.)
I guess I'm saying that Gordon Freeman does indeed "talk" it's just that rather than a voice actor, the player is supposed to put in the dialogue.
In Black Mesa East, Alyx will look at Gordon and smirk when Gordon is being lectured to concerning the Resistance's guidelines, perhaps a quiet snarky comment Gordon gave over to Alyx. When Gordon meets Barney while in disguise, he tries to joke and comfort the possibly freaking out scientist (He had just been teleported into a fascist regime with nothing, alone and friendless, but, turns out he had several friends where he went to.)
I guess I'm saying that Gordon Freeman does indeed "talk" it's just that rather than a voice actor, the player is supposed to put in the dialogue.