Javascript question

gistfile1.txt

// Howler
var words = new Howl({
    src: ['sounds/words.mp3'],
    sprite: {
        all: [0, 693],
        are: [693, 529],
        as: [1228, 644],
        at: [1871, 528],
        but: [2421, 499],
        for: [2924, 655],
        had: [3578, 466],
        have: [4065, 534],
        he: [4600, 546],
        her: [5148, 649],
        his: [5801, 570],
        not: [6382, 575],
        on: [6959, 498],
        one: [7460, 478],
        said: [8044, 701],
        so: [8891, 512],
        they: [9408, 623],
        we: [10051, 533],
        with: [10601, 660],
        you: [11364, 565]
    }
});

var instructions = new Howl({
    src: ['sounds/instructions.mp3'],
    sprite: {
        niceTry: [0, 1096],
        findTheWord: [1096, 2000]
    }
});

// Vue
var app = new Vue({
    el: '#root',
    data: {
        wordsList: [ 'all', 'are', 'as', 'at', 'but', 'for', 'had', 'have', 'he', 'her', 'his', 'not', 'on', 'one', 'said', 'so', 'they', 'we', 'with', 'you' ],
        quizWord: ''
    },
    methods: {
        quizButtonClicked: function (event) {
            // If no quiz word yet
            if (!this.quizWord) {
                // Set quiz word
                this.setQuizWord();
            }
            this.speakQuizWord();
        },
        setQuizWord: function() {
            this.quizWord = this.wordsList[ Math.floor( Math.random() * this.wordsList.length) ];
        },
        speakQuizWord: function() {
            instructions.play('findTheWord');

            // QUESTION: Is there a better way to do the following?

            let quizWord = this.quizWord;
            
            // Fires when the sound finishes playing.
            instructions.once('end', function(){
                words.play(quizWord);
            }.bind(quizWord));
        }
    }
});