This program requires a microphone on your computer. You will need to allow your browser to access it. Quiet sounds will activate the green LED. Louder sounds will activate the yellow LED and very loud sounds activate the red one. Slide the sensitivity slider to the left to make the meter more sensitive or right to require louder sounds to light the red LED.
This is a VU meter like those found on audio mixers. It measures volume. On a real VU meter, lighting the red LED means you've made the sound too loud and you'll distort your signal.
