I didn't have a problem with it, although when I first started playing the alpha all I could think of was Tyrion. However either for the beta or the full game release I have no doubt that they will put some type of effect of Peter's voice to make it sound more like a robot as him talking in his regualr voice isn't very robot like.
Even if they dont add effects to Peter's voice it wont be a massive problem as after a while you'd just it. I'm pretty sure they will change it up in some way though.
I hear more Peter than Tyrian with Ghost. Just his tone is the same, but how he carries his voice is different. Tell me if it is different in Beta. I am still unknown to my status on that.