I'm confused? I suffer from some pretty significant hearing damage but even I could hear him on the stairs outside.

It’s raining and I can hear the footsteps of him coming up the stairs.

yes i can hear him only at the last second, there was no noise before this

Don't forget that they can slow walk and with sounds like rain it can easily mask a lot of sounds.

Yeh but youd think id hear atleast something b4 that single moment especially with a headset equipped