Many people walk around with personal headphones these days -- but very few advertisers have tried to capitalize on this in meaningful ways. One who has done is French train company Thalys, which created interactive billboards that let people listen to the sounds of its destination cities. Agency Rosapark recorded thousands of sounds from across Paris, Brussels and Amsterdam and stored them within the three one-off posters, inviting people to plug their personal headphones.
Each city map contains over a thousand sounds, each with a unique headphone jack; they include the lapping of water in Amsterdam canals, Parisian market traders plying their wares and the wheels of skateboarders in Brussels (and, according to the agency's video, even some overheard passionate cries from a Paris bedroom window). There are also recordings from history, such as recitations of poems and a speech by Charles de Gaulle, used in partnership with the Sound Archives of Paris, l'INA.