unity: plays a sound when you click on the button before loading the load scene in Unity3D

I am trying to reproduce the sound of the button click before loading the scene in unit. However, the sound never plays. Below is my code, I would appreciate help.

public void RestartGame ()
{
audioManager.PlaySound (forwardSound);
StartCoroutine (DelaySceneLoad ("Gameplay"));
}

IEnumerator DelaySceneLoad (string scene)
{
return return new WaitForSeconds (forwardSound.length);
GameTracker.SetGameOver (false);
SceneManager.LoadScene (scene);
}