Scene is the rapid-transit railway station Reeperbahn. At its exits are transistor radios, which permanently transfer the broadcast from radio FSK. 
 

A rapid-transit railway gets into the station, the noise level changes: The noise of the train, loudspeaker announcements, step noises and voices of passengers fill the space. With a microphone the noise is caught and mediated simultaneously by telephone over the institute for Telenautik (at the HfbK) to radio FSK. 
The way of the data over two stations makes an electronic delay, FSK transmits the captured noise as an echo with a delay of approx. 15 seconds. For the passenges it is a small irritation in the everyday life, if they experience the just passed by instant of time from the transistor radios installed in the station as an echo submerged into the radio program.