java 问题

import t.*;import t.event.*;class 信息 extends Label implements MouseListener { sound 声音=new sound(); 信息(String s) { setText(s); addMouseListener(this); setBackground(Color.white); } public void mousePressed(MouseEvent e) { } public void mouseReleased(MouseEvent e) { } public void mouseEntered(MouseEvent e) { ay(); } public void mouseExited(MouseEvent e) { op(); } public void mouseClicked(MouseEvent e) { }}请问sound类怎么写？？？各位，我的积分不多，只能给15分了多多帮助！