With communication and the war work done at Bletchley Park at the centre of the piece, ‘I have a message for you’ is an audio installation designed by Output Arts for the Milton Keynes Fringe Festival. Drawing on the cracking of secret codes and the secrecy surrounding the work of Alan Turing, Output Arts have made a modern facsimile of Turing’s “Delilah” speech scrambling machine using a combination of contemporary technology and the algorithms designed by Turing at the end of the second world war.
Messages were recorded in specially organised sessions at Bletchley Park and Milton Keynes Museum, along with messages gathered from the Output Arts website. This audio was then scrambled using the Delilah algorithms and stored in digital form in the equipment. These messages are descrambled live and heard through a period military field telephone.
The electronics within the descrambler box consist of an Arduino board that interfaces with the telephone ringer and hook switch, and the lights, controls and sensors within the box; Output Arts’ first use of a Raspberry Pi – a British-designed low cost bare-board educational computer with a rich heritage going back to the famous BBC Micro, and using the ARM processor originally designed by Acorn – to run the Delilah algorithm and process the audio; a USB audio output device connected to the phone receiver; and a motion sensor concealed behind the grill in the box.
Listening without speaking alludes to eavesdropping and the covert monitoring of communications. The audience can influence the clarity of the message by adjusting the controls on the machine, giving a physical side to the sense of searching and trying to hang on to the messages. However, the piece includes the deliberate design of interfering with the descrambling process to cause the gradual degradation of the audio so that the messages eventually become engulfed in machine noise before cutting off suddenly to silence. The design of the hut reflects the mood of the huts at Bletchley Park, and the field telephone and desk are on loan from the Milton Keynes Museum collection.
Participants are invited to identify with the audio, recognising shared messages and common experiences – providing a moving insight into personal and shared aspects of life. The difficulty in hearing the messages and their eventual crumbling reminds the participant of their fragility.
Each Friday is PiDay here at Adafruit, be sure to check out our posts, tutorials and new Raspberry Pi related products. Have you tried the new “Adafruit Raspberry Pi Educational Linux Distro” ? It’s our tweaked distribution for teaching electronics using the Raspberry Pi.