Play sound upon Input in Javascript

Using 1 of the default scripts by unity for its FPSInputController but finding some difficulty in playing an audio clip of the player jumping. Code is as follows:

  private var motor : CharacterMotor;
  public var jumpSound : AudioClip;

   // Use this for initialization
   function Awake () {
   motor = GetComponent(CharacterMotor);
  }

  // Update is called once per frame
  function Update () {
  // Get the input vector from keyboard or analog stick
  var directionVector = new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));
 
  if (directionVector != Vector3.zero) {
     // Get the length of the directon vector and then normalize it
     // Dividing by the length is cheaper than normalizing when we already have the length anyway
     var directionLength = directionVector.magnitude;
     directionVector = directionVector / directionLength;
     
     // Make sure the length is no bigger than 1
     directionLength = Mathf.Min(1, directionLength);
     
     // Make the input vector more sensitive towards the extremes and less sensitive in the middle
     // This makes it easier to control slow speeds when using analog sticks
     directionLength = directionLength * directionLength;
     
     // Multiply the normalized direction vector by the modified length
     directionVector = directionVector * directionLength;
 }
 
 // Apply the direction to the CharacterMotor
 motor.inputMoveDirection = transform.rotation * directionVector;
 motor.inputJump = Input.GetButton("Jump");
 if (Input.GetButton("Jump"))
 {
     
     jumpSound.PlayOneShot(jumpSound, 0.3); 
     jumpSound.Play();
 }
 }

 // Require a character controller to be attached to the same game object
 @script RequireComponent (CharacterMotor)
 @script AddComponentMenu ("Character/FPS Input Controller")

Any ideas as to why this is not playing and how I can go about fixing it?