Chris Kaptein offers a two part tutorial where he creates a noise meter on a Jumbotron in After Effects. Chris notes that:
“There are some tutorials out there that show you how to animate EQ bands. But most of them are far too complex and do not achieve a very desirable look. I will show you a simple way to create this animation without using any audio files to drive the animation, and without using overly-complicated expressions.” Check out part one of the tutorial here, with part two here.