Every open plan office I've ever worked in

As a developer, one sometimes need to get into “the zone”. Other developers know this, and you all work quietly together.

Then there are those whose job doesn’t require “going deep”, but mostly consist of transferring knowledge using the lossy medium of voice.

Said folk will come to your corner of the office, think hmmm, it’s nice and quiet here, then go on to make a conference call.

UPDATE: 2017-11-17

I’m glad someone mentioned the Eudamonia Machine, as per Cal Newport’s Deep Work.