Global audio company Squeak E. Clean Studios and agencies VMLY&R Australia and New Zealand created a challenge that serves as a sophisticated recruitment effort for the Australian Navy.

Squeak E. Clean Studios’ head of sound in Melbourne, Paul Le Couteur, converted an image into sound and then embedded that into an audio message complete with voice and sound effects which challenged prospective Navy recruits to find the hidden visual message. The coded message appealed to these would-be intelligence professionals who had to recognize the puzzle and then find the tools required to solve it.

To reveal the hidden missive, the audio, discovered by only the most clever, had to be processed in a spectrogram, which is often used in sound production to repair background noise, crackles, hums and glitches or to isolate elements within a sound file. This is the same technology used by the Australian Navy to intercept, analyze and identify threats at sea. The message connected a tech audience to Navy intelligence roles and targeted the narrow field of intelligence professionals suited to work in the Navy.