An interesting level of this scene is that it implies neither terminator is able to identify a fabricated voice even though they have a full understanding of each other's design. The T-1000 cannot tell it is talking to a T-800 until it realized it has been tricked and the T-800 cannot tell it is talking to a T-1000 until it tricks the other machine.
Of course, it happens over a pay phone so perhaps with the full vocal range in person it would have been different.
Of course, it happens over a pay phone so perhaps with the full vocal range in person it would have been different.