i discovered this is because the passenger bus pulls its sound from the ai-prop wav in the p3d/simobjects/groundvehicles file, so I reduced the volume of this wav and now ok although i am sure there is a better way of doing this.
In future releases can we have all sounds coming from the GSX addon/simobjects folder, that way this issue will finally be resolved as all sounds will be controlled by GSX and not P3D? I suggest 2 volume controls, one for pasenger/internal sounds and one for external sounds
My 2 cents after having had GSX for almost 10 years now, it has always and continues to be fantastic visually, but i think the sounds, including passenger/flight attendant sounds, could be much improved
Best
Charles