The living space of Hong Kong become fewer and fewer. Every people as a part of the crowd of Hong Kong. The sound of the city are around us every one. I used balloon to represent the people on the city. When the people receive the sound, they make the sound at the same time. When people enter this installation, they can heard the sound around them. However, their body when hit the other balloon and made new sounds. You are the balloon , you are the part of the city.