Band room volume meter
My band teacher wants a large size volume meter so band members can see how softly/loudly they are playing at a glance. A visual for "pianissimo" and "fortissimo" and all the others would be helpful. I visualize a 10-20 scale set of large (or clustered) LED's in multiple colors. Maybe 3 feet tall (like a tower speaker) with a built in microphone/sensor at the top with adjustable sensitivity. Think drag race christmas tree meets audio peak meters.
Jonathan Julian commented
Perhaps you can find a sound meter with a large screen. If not, one that sends the data via usb, so it can be intercepted and displayed. http://www.aliexpress.com/fm-store/408231/211227469-494504364/New-Noise-Sound-Level-Digital-Decibel-dB-Meter-USB.html
Eddie H. commented
Very interesting - would a computer app attached to a projector suffice if the visualization was on screen?