Play a beep sound on button click

Admitting you already have something like <div id='btn'>Click to play!</div> in your html, you could do it as simple as:

$('#btn').click( () => new Audio('mp3/audio.mp3').play() );

This is the best IMO because it allow riffle clicking on the button (which is not possible in other answers at the time) and is a one liner.

WORKING DEMO

You could use an audio tag like this:

    <audio id="audio" src="http://www.soundjay.com/button/beep-07.wav" autoplay="false" ></audio>
    <a onclick="playSound();"> Play</a>
    <script>
    function playSound() {
          var sound = document.getElementById("audio");
          sound.play();
      }
    </script>

Here is a Plunker