This is likely caused by your mic not picking it up...
Seems doubtful to me. Loud sounds are really hard to keep out of a raw mic, even if you do choose an appropriate pickup pattern and point the null(s) in the right direction(s).
Source: Front-of-House Engineering with live music...
...or you have an audio filter that either is ignoring what it thinks is a background sound or chopping off a sound at the frequency/pitch of the slam.
That's more likely. If you have a Noise Suppressor on your mic, that's great for your voice, but anything else at all is considered noise to be removed. Music, sound effects, HVAC, traffic, etc. All of that goes away - or at least tries to, with varying success - when you use a Noise Suppressor.
Best to not have it, and actually be that quiet in the room. It might take some work to get there, like finding the actual source of some noise that the suppressor used to take care of, and stopping it physically while you're on, but the end result is more predictable.