A study found that children who attend primary schools with a lot of traffic noise have slower cognitive development. The study done in Barcelona on 38 different schools, showed slower working memory and attention problems. School provides a window where students must be in total concentration, therefore traffic noise at these times is detrimental to their cognitive development.
Photo by: https://www.pexels.com/photo/children-sitting-on-brown-chairs-inside-the-classroom-4019754/