Noise and detection system

Hi. I really need to create a noise system for my game so that when my character makes noise - a bar of noise will fill and game over when it’s full. Can you please advice on where to start reading, watching? What are they ways to implement this? Maybe it should be just character’s speed that pretends to be noise, and colliding with objects also increasing the “noice amount” variable?
If yes, how to make this noise system turn on only after specific event, or maybe make it noticable only to one enemy character? Please halp

Not even a single reply on such a good topic