Noise and open plan offices

[sawyl]

This, from a piece on the damaging effects of noise pollution, is interesting:

Another study, by Cornell University in New York, found that workers in an open-plan office with constant exposure to hubbub from machinery, telephones and office chatter had higher levels of adrenaline in their urine than workers in a quiet, self-contained work station. The open-plan group were also less effective at puzzle solving than the quiet group, who slept better, had better digestion, and were less irritable.

I wonder if the drop in effectiveness is quantifiable and whether it can be balanced against the cheaper construction costs of open plan?