const AMBIENT_LIFT = 40;

// from https://www.unep.org/resources/frontiers-2022-noise-blazes-and-mismatches

const cities = ['Dhaka', 'Ho Chi Minh City', 'New York', 'Hong Kong', 'London', 'Paris', 'Los Angeles'];

const dBa = [119, 103, 95, 89, 86, 80, 71];

const latlong = [[23.78, 90.34], [10.75, 106.07], [40.69, -74.14], [22.35, 113.97], [51.53, -0.266], [48.86, 2.265], [34.02, -118.74]];

​

let mic;

​

// convert from linear volume [0,1] to decibel scale

function todB(vol) {

  return Math.log10(vol) * 20;

}

​

function setup() {

  createCanvas(400, 400);

  noStroke();

  textFont("IBM Plex Mono");

  frameRate(12);

  mic = new p5.AudioIn();

  mic.start();

}

​

function draw() {

  background(0);

  let vol = mic.getLevel();

  // it seems like it's very difficult to get above 0.5 volume, so this

  // lets us adjust the "max" volume

  const usableVol = map(vol, 0, 0.5, 0, 1);

  let city;

  let coords;

  for (let i = 0; i < dBa.length; i++) {

    if (dBa[i] > todB(usableVol) + AMBIENT_LIFT + 71) {

      city = cities[i];

      coords = latlong[i];

    }

  }

  // draw a grid of circles

  for (let i = 1; i < 9; i++) {

    for (let j = 1; j < 6; j++) {

      if (random() > usableVol) {

        circle(40 * i + 20, 40 * j + 20, 40);

      }

      if (random() > usableVol) {

        fill(255, 0, 0);

      } else {

        fill(255);

      }

    }

  }

  fill(255);

  const timeNow = new Date();

  const displayText = city + " / SOUND" + "\n" +

        "\n" +

        "LAT " + coords[0] + " LONG " + coords[1] + "\n" +

        timeNow.toDateString() + "\n" +

        timeNow.toTimeString() + "\n" + 

        (todB(usableVol) + AMBIENT_LIFT + 71);

  text(displayText, 40, 300);

}