The program sound comes from your phone's speaker.
An earphone makes listening easier.

Each program displays one or two photos related to the program

Many newer phones have the code reader installed. Launch the application, or activate your camera, and scan the code. Follow the prompts on you version to visit the website and play the audio.

Your phone may have NFC built in (newer Android) or may require a downloaded app (iPhones require an NFC App). With NFC activated, merely bring your phone near the logo on the sign.