In all the soundpacks I have used, moving onto/off of an object that costs many movement points causes a long and obnoxious sound to play. This is made worse for things like forests and cargo spaces on cars where constant moving causes the sounds to clip over themselves.
I modified these three sound clips to be much shorter and quieter.
https://drive.google.com/open?id=1iTwT3vmZZHAM9MmKBTBRR6yFGBHMWeQ0
To install it, go to cdda\data\sound(your soundpack)\env\walk and replace the three ‘clear_obstacle’ files with the ones from the drive. (I am using CDDA-Soundpack, so it may be in a different location for you)