I had a quiet private office for my first five years working in this career. I know that I felt more productive, and when my next job switched to a quiet cubicle with that "library" feel, I remember only a slight loss of productivity. However, in my third job, I switched to a noisier cubicle environment, and remember feeling like productivity dropped through the floor. Next I moved to a large open environment with high noise levels, and felt another precipitous drop in productivity. So much so that I organized a revolt, and managed to secure moderately quiet cubicles for the team. (A small group had requested the move to the open environment a year earlier, and common feeling was that everyone was happier. I didn't believe it so I set up an anonymous vote, and received 16 votes to return to cubicles, 1 vote of "don't care", and exactly 1 vote to keep the open plan.)
I worked in those cubicles for eight years, but recently quit to start my own company.
Now that I have a private office again, my only distraction is the cat, and I've noticed increasing productivity each week. The most telling thing is that I've started to have days where I can stay "in flow" for 4 hour chunks. It feels like I sit down to start writing, type for 5 minutes, take a lunch break, type 5 more minutes, and then my actual 8-10 hour day is done.

That said, I have mixed feelings about it. Poor management decisions like this are part of the reason start-up companies have a chance to unseat established players in a market.