After reading said article I decided to conduct trials of my own.
I found a suitable cobbled location and marked a circle 17 metres radius. Then I got the wife to run three circles flat out whilst dragging an empty wheelie bin. After this trial run I switched on the noise level meter to record readings. After a short break of 30 seconds I waved the flag and she began to run. This time not as fast as the first three circles and I couldn't understand why. The noise level only reached 74dB.