Here he is again! I made a custom script with a brunoSound variable !!! ... attach this javascript script to an object, add an audio source and then add a sound file in the inspector next to the variable brunoSound.

var brunoSound : AudioClip;

function Update() {

if (Input.GetButtonDown("Fire1")
{
audio.PlayOneShot(brunoSound);
}
}
@script RequireComponent(AudioSource)

It is easy:

 if (Input.GetKeyDown("s"))
 {
     audio.Play();
 }