Reporting in Landscape and Urban Planning, the researchers found that all groups, even those wearing noise-cancelling headphones, experienced a reduction in blood pressure, heart rate and cortisol levels, demonstrating that simply going for a walk was beneficial. Adding in rare birdsong did not reduce stress more than natural birdsong but, interestingly, paying attention to birdsong did. No matter where you live, birdsong may be just what the doctor ordered.