Whispering “Shhhhhh” is not the most effective way to get people to shut up. Especially in public spaces, and especially in public libraries.
So, let’s shut their mouth with a sense of guilt.
This light is installed in the library. It detects noise, and as the noise increases, the luminance decreases. If you’re speaking too loud in the library, the room gets darker and darker. Eventually, everyone in the room won’t be able to read. Is that what you expected? Probably not, And because you are now unexpectedly the center of attention in this darkening room, pieced of hundreds of readers’ eyes filled with ire, your sense of guilt will skyrocket and you’ll definitely shut up.
After the room becomes silent, the light will turn back on. Then, everyone can read in silence, and everyone wins :))))))))