Sudden wind noise

Hi, I love FSRealistic and its one of my favourite addons. But one thing that really annoys me is the sudden wind noise.

Does anyone know if there is a way to smoothly increase wind noise with speed. If I have the slider set to 50%, it is all quiet at less than 50%. But as soon as it ticks over 50%, this loud noise suddenly starts. Its highly unrealistic. Can someone please give me a pointer if I have missed something obvious?

Thanks, Sam