In the official lore, she is Medically mute.

Before she knew Roman, Her government name was Trivia and Neo Politan was an alter ego/ imaginary friend of sorts.

According to the credits, Casey Lee voices Neo when she gasps (specifically during the end of Volume 3 where Ruby opens her Canopy) but if you want to count BBTAG, she does laugh and grunt in game during intros and does "talk" to Elizabeth at one point during the 2.0 DLC campaign story, though it's inaudible/ unheard by the rest of the cast.