The Denver Museum of Nature and Science's http://www.dmns.org/main/en/ health section includes an interactive exhibit demonstrating the correlation between noise and stress. You put 2 fingers in metal slots, which connects you somehow to something that triggers electric current. (I'm a writer, not a scientist!) That is connected to 4 columns containing lights. The more lights lit, the more stressed you are.
I put on headphones and listened to directions. The first column of lights went 3/4 of the way to the top. Next, the voice told me to close my eyes and breathe deeply, tuning out the sounds around. The lights in the next column went only 1/4 of the way to the top. Then the voice asked me to choose 1 of 4 scenarios and close my eyes. I chose the Saturday morning scenario, thinking that would be least stressful. Wrong! Dogs barked, kids screamed and cried, the phone and doorbell rang simultaneously. Guess where the lights were? Right! At the top of the column! Last, the voice told me to close my eyes and imagine an oceanside scene. I heard waves lapping at the shore. Breathe deeply. When I opened my eyes, the lights on the 4th column barely registered.
This exercise dramatically demonstrated the power of quiet and offers suggestions for calming ourselves when we are stressed. Take a deep breath and a shhh break. Aaaaaah!