They also have a blog supposedly dedicated to noise awareness with headlines like "School kids and night club owners join forces against noise pollution", when, in fact, no such thing has happened. School kids shouted at their billboards to see if they could make it jump, and a nightclub owner took pictures of the billboard near his nightclub as proof that his club isn't that loud at night. I fail to see this as constituting "joining forces", or even working against noise pollution, really, so I won't link that blog.
Another annoyance: their website asks "Did you know that an increase of just three decibels doubles the intensity of the noise?" While technically correct, this question misleads most of their readers because, outside of a technical context, it suggests to many people that a change of 3 dB will sound like a doubling in loundness, which it won't. Psychoacoustic research tells us that a change from 6 to 10 dB sounds like a doubling1. But I guess that doesn't sell as many washing machines.
Finally, while it's cool that you can view the current noise intensities of three of the major cities online (with histories!) It's a shame that the dB Meters seem to max out at 95 dB, which is only 5 dB above the range of volume levels given for a major road, according to wikipedia, and much quieter than, say, thunder, so you couldn't use this to get an accurate account of actual average noise levels over time -- at least not of this spot in Berlin:
Click for Full Sized Chart
Despite the minor annoyances, I love the ad campaign, and I love the billboards!
Thanks to laughing squid.
1Here are some citations given in a standard acoustics text, The Science of Sound, by Thomas D. Rossing. I haven't checked them myself, but the 6-10 dB figure is commonly used:
Stevens, S. S., and G. Stevens (1975). Pychophysics Introduction to its Perceptual, Neural and Social Prospecta. New York: Wiley.
Warren, R.M. (1970). "Elimination of Biases in Loudness Judgements for Tones," J. Acoust. Soc. Am. 48:1397.