test.js

var context = new AudioContext()
var o = null
var g = null
document.addEventListener('DOMContentLoaded', function () {
  $(".js_play_sound").on("click", function (e) {
    e.preventDefault()
    var $target = $(e.target)
    eval($target.data("source"))
  })
  $(".js_stop_sound").on("click", function (e) {
    e.preventDefault()
    o.stop()
  })
}, false)

function example1() {
  o = context.createOscillator()
  o.type = "sine"
  o.connect(context.destination)
  o.start()
}

function example2() {
  o = context.createOscillator()
  g = context.createGain()
  o.connect(g)
  g.connect(context.destination)
  o.start(0)
}

function example2Stop(decreaseTime) {
  g.gain.exponentialRampToValueAtTime(0.00001, context.currentTime + decreaseTime)
}

function example3(type, x) {
  o = context.createOscillator()
  g = context.createGain()
  o.connect(g)
  o.type = type
  g.connect(context.destination)
  o.start(0)
  g.gain.exponentialRampToValueAtTime(0.00001, context.currentTime + x)
}

function example4(frequency, type) {
  o = context.createOscillator()
  g = context.createGain()
  o.type = type
  o.connect(g)
  o.frequency.value = frequency
  g.connect(context.destination)
  o.start(0)
  g.gain.exponentialRampToValueAtTime(0.00001, context.currentTime + 1)
}