Researchers have determined that “as little as 40 decibels of traffic noise – the typical level of background noise in an office environment or kitchen – has a detrimental effect on cognitive performance. Researchers at Chalmers’ Division of Applied Acoustics have conducted a laboratory study in which test subjects took concentration tests while being exposed to background traffic noise. . . . subjects had significantly poorer results on the performance test, and also felt that the task was more difficult…