let vol;

function setup() {

  createCanvas(400, 400);

  mic = new p5.AudioIn();

  mic.start();

}

​

function draw() {

  background(220);

 vol = mic.getLevel();

  text(vol, 10,10)

  let sze = map(vol ,0,1,20,height)

  circle(width/2,height/2,sze)

}