function setup() {

  createCanvas(400, 400);

  mic = new p5.AudioIn();

  mic.start();

}

​

//----------------------------------------------

function draw() {

  background(220);

​

  // Get the overall volume (between 0.0 and 1.0);

  // Smooth the volume variable with a running average

  let v = mic.getLevel();

  let smoothing = 0.9; // must be between 0...1

  let A = smoothing; 

  let B = 1.0-A; 

  theCurrentVolume = (A * theCurrentVolume) + (B * v);

​

  fill('black');

  noStroke();

​

  let diam = map(theCurrentVolume, 0,1, 10,1000);

  circle(200, 200, diam);

  textSize(24); 

  text(nf(theCurrentVolume,1,3), 20,30); 

}