Have never had a WG not make noise. But I have with civvies. There was this one time when I was pestering a former GF for sex all day long and she finally gave in. She just laid there with a moody look on her face and not making a sound. I did my business and to be honest I actually kinda enjoyed it.. I got mine. I suspect she enjoyed it too in a weird kinda way.
If it happened with a WG, well it would depend on what she's advertising and what I am excepting out of her. If I was just going for a pump and dump with a moody Romanian, well I guess I could deal with that, as long as she was hot and I cum. But if it was a highly rated Polish or British WG who advertises a sensual GFE, I might be a bit annoyed. But if you're enjoying it then I wouldn't worry about it. If it does disconcert you, then well, just find another WG. That's what I'd do, there's always other WG's who will take your money and put on a different kind of performance for you.