In 2003, Berlin-based sound artist Christina Kubisch began an ongoing project called "Electrical Walks." This project employs specially built headphones that receive electromagnetic signals from the environment and convert them into sound. Kubisch maps a given territory, noting "hot spots" (ATM machines, security systems, electronic cash registers, subway systems, etc.) where the signals are particularly strong or interesting. She then loans the headphones to the public, allowing participants to undertake an auditory drive through the invisible network of electromagnetic information.