Walking through an unmaintained wooded area involves navigating through leaves and fallen branches, as well as standing bushes. These things make noise. The game doesn't have this mechanic as it should, solution:
Create a clone of the terrain, add random noise in areas where there are trees that raise it above the terrain, texture it to be sticks, create collision box but make it permeable. Players still walk on the actual ground, but when passing through the other terrain, walking sound changes. (Similar to how bushes work in vanilla.)
In the game, the loudness of boots is poorly represented, someone who is skilled at walking quietly in boots in a sound sensitive environment is going to be much quieter than someone who is not skilled walking in sneakers, or even barefoot. Things like: more loud when more overloaded, make sense, but for now you could just temporarily lower the sound of boots so infected detect them less, make shoes weigh more soaked, and make the sneakers able to be wrung out to some degree to balance.
As it stands boots feel entirely useless, and in real life you would probably hold onto a good pair of boots for dear life, in the game, you hardly need anything other than the dress shoes and a sewing kit to run a character for Gregorian days.