Quiet down in there!

At many modern construction sites in Japan, passersby will see one or more of these displayed on the outer wall of the construction area. The device uses a finely calibrated microphone to measure noise and vibration and the readout displays the readings in real time to inform the public of their exposure readings while they're in the area. This also helps construction site foremen to be sure they're operating within the set limits.

So even construction sites are courteous. Pretty damn kool, I think!