Some sounds gone, some there...help

nip

I'm having a sound problem. Driving me nuts.

I can hear: other people's footsteps, other alien's sounds, gunfire from other people.

I can't hear: my own gunfire, my reloading sounds, my voice binds ("standing by"), the comm or any other teammate's mic, my footsteps.

Any ideas what would cause "selective hearing" as my wife would say?

Thanks in advance.