nBump settings for runway only

Does anyone know how to set nBump.wav to only make sound when on the runway? It would add more realism to the effect.

the download is an add on for the free PM Sounds software and the nbump add on sound can be found in our downloads section at MyCockpit. :)

Already downloaded and installed. I was looking to improve on the effect, as it plays during taxi when there are no runway lights.