christopher

Just get in the habit of checking for your keys before you go through any door. It takes no mental effort once it's a habit. If they aren't in your pocket (or in my case a lanyard) then they are in that room or vehicle, so you should recover them before going out. This method worked for me 100% for decades. It only failed after I got married and my wife started stealing them. But it's usually not too hard to find her.

No toca los PopOS!

PulseEffects can moderate the high-volumed sounds too. It has a complex set of controls and filters, and I'm not a sound engineer, so I just followed someone else's recipe.