You try to control for statistical variables like pollution, occupation, and personal habits. I don't know anything about medical statistics, so I'm just accept

You try to control for statistical variables like pollution, occupation, and personal habits. I don't know anything about medical statistics, so I'm just accepting the conclusions of the road noise research. This paper should be helpful if you want to dig into the methodology one can use. https://academic.oup.com/eurheartj/article/32/6/737/497025 https://academic.oup.com/eurheartj/article/32/6/737/497025