Two ear or one-ear: what should I choose?

A two-ear or Binaural headset gives more isolation and can feel calmer in busy spaces.  
A single-ear or monaural headset keeps you aware of colleagues and the room.
If you need to hear announcements or quick questions, a monaural one eared headset can be the better fit. If you’re in long meetings, and you want fewer distractions, over-ear, binaural is often more comfortable. The “right” answer is usually tied to how interactive your workspace is, not to audio specs alone.