Wait for clip finish and activate other audio source

Hi, I've a little question.

I want to play a sound and desactivate ALL others audio sources if the player pick some stuffs. In my script bellow, the sound stop and the new play very well. But I'm unable to reactivate all the others audio sources AFTER the clip has finished...

Here my C# script :

 public class Sign : MonoBehaviour {
     private bool revertFogState = false;
     public Font f;
     public int SignsFound = 0;
     public AudioClip pickSound;
     public AudioClip DANCE;
     public Transform explosion;
     public Transform win;
     private GameObject toDestroy;
     private bool destroyObjectSwitch;
     private bool pickup;
     private bool collided;
     private int tempo;        
 
     void Start () {
         this.destroyObjectSwitch = false;
         this.pickup = false;
         this.collided = false;
     }
 
     void Update () {
         if(Input.GetButton("Fire1")){
             this.pickup = true;
         }else{
             this.pickup = false;    
         }    
         Debug.Log ("pickup : "+this.pickup+" Collided : "+this.collided);
         if (Input.GetButtonDown("Pickup") && this.collided == true){
             AudioSource.PlayClipAtPoint(pickSound, transform.position );
             Instantiate(explosion, transform.position, transform.rotation);
             Destroy(this.toDestroy.gameObject);
             this.SignsFound++;   
             this.pickup = false;
             this.collided = false;
             this.tempo = 100;
             if (SignsFound == 1){
                 AudioSource[] audios = FindObjectsOfType(typeof(AudioSource)) as AudioSource[];
                 foreach(AudioSource aud in audios)
                 aud.volume = 0;            
                 AudioSource.PlayClipAtPoint(DANCE, transform.position );
                 Instantiate(win);
                 yield return new WaitForSeconds(audio.clip.length);
                 AudioSource[] audios = FindObjectsOfType(typeof(AudioSource)) as AudioSource[];
                 foreach(AudioSource aud in audios)
                 aud.volume = 0;
                 RenderSettings.fog = revertFogState;     
            }                
        }
        if(this.tempo>0)this.tempo--;        
     }
       
     void OnTriggerEnter(Collider other){
         Debug.Log (other.gameObject.name);
         if(other.gameObject.tag == "Sign" ){
             this.collided = true;
             this.toDestroy = other.gameObject;
         }    
     }
     
     void OnTriggerExit(Collider other){
         this.collided = false;
         this.toDestroy = null;
     }
     
     void OnGUI(){
         if(this.tempo>0)
             GUI.Label (new Rect (Screen.width/2-100,Screen.height/2-10,500,500), "Tu as "+this.SignsFound+" panneau (x) SUR 5.");
             GUI.skin.font = f;
     }
 }

I tried to make a Yield returne new for the clip, but I cant reactivate the others sounds. Can you help me ? ^^