now I'm doing the multi choice from lists but the voice didn't come out. what should i do?

Cannot implicitly convert type void' to UnityEngine.AudioSource'

using UnityEngine; using System.Collections; using UnityEngine.UI; using System.Collections.Generic;

public class test : MonoBehaviour {

 string[,] data = new string[3,3];
 string[] WrongAnswer;
 public Text Answer1;
 public Text Answer2;
 public AudioClip clip;
 public AudioSource Sound_Question;
 public AudioSource Sound;
 public int question = 0;
 List<Choice> list = new List<Choice>();
 // Use this for initialization
 void Start () {
     init();
     showQuestion();
     Sound = GetComponent<AudioSource> ();

 }

    public void showQuestion()
 {
     Sound_Question = list[question].Question;

     int rand = Random.Range(1, 3);

     if(rand == 1)
     {
         Answer1.text = list[question].CorrectAnswer;
         Answer2.text = list[question].WrongAnswer[Random.Range(0, list[question].WrongAnswer.Length)];

         Answer1.GetComponent<Property>().isCorrect = true;
         Answer2.GetComponent<Property>().isCorrect = false;
     }
     else
     {
         Answer2.text = list[question].CorrectAnswer;
         Answer1.text = list[question].WrongAnswer[Random.Range(0, list[question].WrongAnswer.Length)];

         Answer2.GetComponent<Property>().isCorrect = true;
         Answer1.GetComponent<Property>().isCorrect = false;
     }

 }

 public void init()
 {
     list.Add(new Choice()
     {
         Question = Sound.GetComponent<AudioSource>(),
         CorrectAnswer="ANT",
         WrongAnswer = new string[] { "CAT","RAT","IN"}
     });
     list.Add(new Choice()
     {
         Question = Sound2.GetComponent<AudioSource>(),
         CorrectAnswer = "SNAKE",
         WrongAnswer = new string[] { "IN", "TOP", "SPIN" }
     });
 }

 void Question()
 {
     int pos = Random.Range(1, 3);
     if (pos == 1)
     {
         Answer1.text = data[pos, question];
         Answer2.text = data[pos + 1, question];

     }
     else if (pos == 2)
     {
         Answer1.text = data[pos, question];
         Answer2.text = data[pos - 1, question];

     }
 }

}