How to Perform Sound Classification with ml5.js?

// To store sound classifier object
let classify;

// This varible is to keep track of 
// the word that model predicts
let predictedWord = "";

// This array consists of words that
// the SpeechCommand18w model can predict.
let words = [
    "zero",
    "three",
    "six",
    "nine",
    "left",
    "stop",
    "one",
    "four",
    "seven",
    "up",
    "right",
    "yes",
    "two",
    "five",
    "eight",
    "down",
    "go",
    "no",
];

/* 
The 'preload' function loads SpeechCommand18w
with a confidence threshold of 0.6 .
This means that the model only accepts 
prediction above this confidence level.
*/
function preload() {
    let options = { probabilityThreshold: 0.6 };
    classify = ml5.soundClassifier("SpeechCommands18w", options);
}

/*
The 'setup' function runs once when program starts.
Here, a canvas is created and classification process starts.
The 'gotresult' function handle predictions and errors. 
*/
function setup() {
    createCanvas(650, 450);
    classify.classifyStart(gotResult);
}

/*
The 'gotResult' function is called
when classifier makes a prediction
Results to the prediction are in an 
array ordered by confidence.
The first label is one the model feels
most confident about, at indicated by result[0].
*/
function gotResult(results) {
    console.log(results);
    predictedWord = results[0].label;
}

/*
This function is to draw a list of
18 words recognized by model in tha canvas.
*/
function displayWords() {
    textAlign(CENTER, CENTER);
    textSize(28);
    fill(0);
    text("Speak one of these words!", width / 2, 40);
    let x = 125;
    let y = 150;
    for (let i = 0; i < words.length; i++) {
        fill(120);
        text(words[i], x, y);
        y += 50;
        if ((i + 1) % 6 === 0) {
            x += 200;
            y = 150;
        }
    }
}

/*
This function runs continuously in a
loop, it updates and renders
the canvas repeatedly.
It shows the predicted word.
*/
function draw() {
    background(249);
    displayWords();
    if (predictedWord !== "") {
        fill("#2f8d46");
        textAlign(CENTER, CENTER);
        textSize(70);
        text(predictedWord, width / 2, 100);
    }
}