Audio.PlayOneShot-Problem

hello community, I have another problem with one of my new codes:
I want a script to play a sound only the time I hold a special button, but I don't exactly know, which word to use, at the moment, that's my script:

Code (csharp):

1. var speed = 2.5;
2. var openSpeed = 2.5;
3. var useTime = 6.0;
4. var useKey : String;
5. var wheel : Transform;
6. var rotate : boolean = true;
7. var door : Transform;
8. var openDoor : boolean = true;
9. var wheelSound : AudioClip;
10.  
11. function OnTriggerStay () {
12.     if (Input.GetKey (useKey)) {
13.         if (rotate == true) {
14.             wheel.Rotate (0, speed, 0);
15.             audio.PlayOneShot (wheelSound, 0.5);
16.             }
17.         if (openDoor == true) {
18.             door.Translate (0, openSpeed, 0);
19.             Invoke ("StopDoor", useTime);
20.             }
21.         }
22.     }
23.  
24. function StopDoor () {
25.     openDoor = false;
26.     }
27.    
28. @script RequireComponent (AudioSource)