sound signal shell

例句：

1. 1. The sound of the waves crashing against the shore is soothing.
   海浪拍打岸边的声音令人感到宁静。
2. 2. The teacher's voice carried across the room.
   老师的声音传遍了整个房间。
3. 3. The sound of laughter filled the room.
   房间里充满了笑声。