I am sitting in a library, which has three different "volume" areas: silent, whisper, and talk. Unfortunately, not everyone respects the signs. A single conversation can make the silent section quite difficult to work in, arguably more difficult than the talk section, where a constant hum phases the
single voices out.
Since the role of the stuck-up nerd shushing people is so ungrateful, it is best outsourced to a machine, which feels no shame. Isoshush is a volume-activated shush box. It detects when conversation-like noises above a chosen dB-level persist, and sternly shushes, until the volume-infringers cease and desist.
The deluxe version features an LCD screen, sporting a librarian's disapproving frown when in shush mode.