> active noise cancelling has the same effect as putting earplugs in due to wave mechanics.
Simply from experience, I would disagree with this. Every time I have ever enabled active noise cancelling, I have experienced an increase in eardrum-pressure, volume, or both (both with and without music playing).
I understand that wave mechanics would theoretically work as you state, but in practice, does not.
I use concert earplugs now, they are invisible unless someone really looks in my ears, and they attenuate all frequencies equally. This way I can also use them at concerts and they won't ruin the music, just make it much quieter across every frequency.
The open office can't die soon enough, what an absurd fad this is.