(function (exports) {
	'use strict';

	var hearingTest = HearingTest;
	var hearing = hearingTest.init();

	var app = new Vue({
		el: '#hearing-test-app',
		data: {
			isPlaySound: false,
			frequency: 1000
		},
		methods: {
			changeFrequency: function() {
				hearing.sound.frequency.value = this.frequency;
			},

			playSound: function() {
				hearingTest.playSound();
				this.isPlaySound = true;
			},

			stopSound: function() {
				hearingTest.stopSound();
				this.isPlaySound = false;
			}
		}
	});
}(window));

(function (exports) {
	'use strict';

	var hearingTest = HearingTest;

	var app = new Vue({
		el: '#hearing-test-app',
		data: {
			isPlaySound: false,
			frequency: 1000
		},
		methods: {
			changeFrequency: function() {
				hearing.sound.frequency.value = this.frequency;
			},

			playSound: function() {
				hearingTest.playSound();
				this.isPlaySound = true;
			},

			stopSound: function() {
				hearingTest.stopSound();
				this.isPlaySound = false;
			}
		}
	});
}(window));

Remove hearingTest.init() call