Like a traffic light the lamp changes from green to amber to red as noise levels increase - and teachers say it is having the desired effect.
The lamp is being tested on a class of 28 nine-year-olds at the private Kant primary school in the Steglitz district. Ulrich Gaul, headteacher, said: "The class was one of the noisiest in the school and drew complaints from neighbouring classes. But since the light was installed at the beginning of the year, they have become a lot more controlled, and it's coming from themselves, not from a teacher."
Bernd Richter, school psychologist, said the lamp would help teachers as much as pupils, because noisy environments could give staff headaches, hearing trouble and depression. The noise-sensitive lamps cost 400 euros (pound;280) and can be bought online from the office furnishings company Org-Delta (www.org-delta.de).