This raises an interesting point about design. I've worked for small (<8 person) startups where the open floor plan worked well. I now work for a large company (~50 people on my floor). We still use what I would call an "open floor plan" at the large company, but it has been carefully designed such that I only have 6 or so people in my immediate vicinity. Despite both being "open", they very different in layout from the each other.

At the large company, I can't generally here what's being discussed by folks in the next group over, except maybe as low background noise. I don't generally get distracted and I am easily able to grab my teammates' attention when I need it.