At the Oshman Engineering Design Kitchen (OEDK) makerspace at Rice University, there are a number of powerful tools and large machinery. While eye protection and glove use has been widely adopted there, hearing protection requirements can seem a bit more abstract, and are not always followed. To encourage people to safeguard these vital sensory organs, the “Ring the Decibels” team there has come up with an Unsafe Noise Level Alert System that shows when your ears may be in danger.
Sound levels are detected by an analog sound level meter, which passes this data on to an Arduino Uno. A WS2812B programmable LED strip lights up progressively in green, yellow, and red, and when a harmful sound threshold is hit, separate LEDs under an acrylic cutout of headphones blink red to indicate danger. The “VU meter” section LEDs also blink away when levels are in the “danger zone,” further reinforcing that you should really protect your ears.
The physical build is made with two circular pieces or laser cut wood, affixed together using standoffs. The top wood section holds the laser-cut acrylic that LEDs shine through, while the bottom section acts as a platform for electronics. For another take on this idea, you might also check out the “Hello Light” featured here. That particular take on things works as a sort of sound stack light, and was envisioned as a device for helping to control children’s noise levels. As you might guess, the concept wasn’t so effective in that arena!