ChecBox set unchecked when scroll listView. My solution interferes whit setOnCheckedChangeListener

I have a listView whit many checkBox, that when are checked at true start a TextToSpeach. Now the problem is that when i scroll in the listView all the CheckBox that i have checked are reseted at unchecked. So have found any tutorials for a solution. But whit solution that i have used, the state of the checkbox is saved in a variable, and when the checkBox is again visible is rechecked. So the TextToSpeach start again. Here is my code (I know that isn't a good code):

public class MyAdapter extends ArrayAdapter<Model> {
private TreeSet mSeparatorsSet = new TreeSet();
private final List<Model> list;
private final Activity context;
public String textToSay;

public MyAdapter(Activity context, List<Model> list) {
    super(context, R.layout.row, list);

    this.context = context;
    this.list = list;
}

@Override
public int getItemViewType(int position) {
    if (list.get(position).getVersion() == 0) {
        return 0;
    }
    return 1;
}

@Override
public int getViewTypeCount() {
    return 2;
}

static class ViewHolder {
    public TextView text;
    public TextView text2;
    public CheckBox checkbox;
    public TextView textSeparator;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    ViewHolder viewHolder = null;

    if (this.getItemViewType(position)== 0){
        if (convertView == null) {
            LayoutInflater inflator = context.getLayoutInflater();
            viewHolder = new ViewHolder();
            convertView = inflator.inflate(R.layout.title_row, null);
            viewHolder.textSeparator = (TextView) convertView.findViewById(R.id.textView);

            convertView.setTag(viewHolder);
            convertView.setTag(R.id.textView, viewHolder.textSeparator);

        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }
        viewHolder.textSeparator.setText(list.get(position).getName());
        return convertView;
    }

    if (convertView == null) {
        LayoutInflater inflator = context.getLayoutInflater();
        convertView = inflator.inflate(R.layout.row, null);
        viewHolder = new ViewHolder();

        viewHolder.text = (TextView) convertView.findViewById(R.id.label);
        viewHolder.text2 = (TextView)convertView.findViewById(R.id.label2);
        viewHolder.checkbox = (CheckBox) convertView.findViewById(R.id.checkBox);

        convertView.setTag(viewHolder);
        convertView.setTag(R.id.label, viewHolder.text);
        convertView.setTag(R.id.checkBox, viewHolder.checkbox);
    } else {
        viewHolder = (ViewHolder) convertView.getTag();
    }

    viewHolder.checkbox.setTag(position); // This line is important.
    viewHolder.text.setText(list.get(position).getName());
    viewHolder.text2.setText(list.get(position).getName2());
    viewHolder.checkbox.setChecked(list.get(position).isSelected());
    final CheckBox chk = (CheckBox)convertView.findViewById(R.id.checkBox);
    final View finalConvertView = convertView;

    chk.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            int getPosition = (Integer) buttonView.getTag();
            list.get(getPosition).setSelected(buttonView.isChecked()); // Set the value of checkbox to maintain its state.

            if (isChecked) {
                String textPart1 = " ";
                String textPart2 = " ";
                String textToSay = " ";

                TextView label2 = (TextView) finalConvertView.findViewById(R.id.label2);
                TextView label1 = (TextView) finalConvertView.findViewById(R.id.label);



                textPart1 = label2.getText().toString();
                if ((getPosition + 1) < list.size()) {
                    if(list.get(getPosition+1).getVersion() == 0){
                        textPart2 = list.get(getPosition + 2).getName();
                    } else {
                        textPart2 = list.get(getPosition + 1).getName();
                    }
                }
                textToSay = textPart1 +
                        "\n" + "." +
                        "\n" + "." +
                        "\n" + "." +
                        "\n" + "." +
                        "\n" + "." +
                        "\n" + "." +
                        "\n" + "." +
                        "\n" + "." +
                        "\n" + "." +
                        "\n" + "." +
                        "\n" + "." +
                        textPart2;

                OneFragment.startSpeak(textToSay);

            }
        }

    });
    return convertView;
}
}

So anyone have an idea how i can solv my problem?