Classroom Noise Meter and Its Three Sleeping Kittens

Why it surfaced

This is a narrow classroom tool with an unusually humane interface: students keep three kittens asleep rather than watching an alarm bounce around the screen. It also explains its privacy model clearly—the browser measures live amplitude locally, without recording, transcribing, or uploading audio—and includes sensitivity controls, full-screen display, and activity-specific guidance.

A free browser-based classroom noise monitor that maps live microphone levels to four relative sound bands and a visual kitten signal.