First person shooter : Footsteps!

I am really asking two different things here:

  1. Is there a basic script that can be placed on the default FPSController in Unity5 that adjust the volume of your footsteps depending on how fast you’re moving or on which surface you are walking on.

  2. I am also in need of an npc script where said npc reacts to the sound of your footsteps.

So yeah if you’ve ever played one of the early Thief games then you might know where I am coming from.

Also I am a beginner so please try to explain this to me as simple as you possibly can.