And the DC staff wears hearing protection when they're working among the racks.

I wish that hearing protection had been required or at least offered when I used to visit data centers frequently. They made a big deal of the fire suppression training, but never even suggested ear plugs. 20 year-old me had no idea how bad that noise was for my ears. I hope the staff there were wearing plugs, but it was never apparent.

You only get one set of ears.

I suspect I still have the record for most expletives used in front of the headmaster at my old school because someone turned a few kW speaker on while I was wiring something under the stage - i.e. I wasn't pleased.

That still blows my mind. Coming from telecom where everything prior to the #5 ESS was convection cooled, a happy office is a quiet office.

Data got weird.

I'm assuming telecom had very different volume-power requirements. Where I grew up there were many mid-city phone switches that were large, concrete exterior, almost windowless, buildings.