The Australian Navy needed to recruit Electronic Spectrum System Operators. It’s an intelligence role that’s difficult to recruit for and involves identifying threats at sea by manipulating frequencies in the electromagnetic spectrum – also known as The Invisible Battlefield. So, that’s where we ran our ad. With a small budget for social media, we created a single audio file that was so much more than something to listen to. We challenged people to analyse it, decode it, manipulate its frequency content and discover its hidden message – a poster, painted with sound.

The Audio Ad You Can See is 56 seconds of audio. But hidden inside the audio is a poster – our recruitment ad. To find it, the audio needs to be processed with a spectrogram. It’s a tool that analyses frequencies in the electromagnetic spectrum and is used by audio engineers to repair sound and remove unwanted hisses, hums, buzzes and background noise. It’s also used by the Navy to analyse frequencies at sea and identify threats that can’t be seen. Only those with the right skills and problem-solving abilities could find the hidden message and get the link to take them directly to the job listing. The result was an audio ad that was also a print ad, a social post, user-generated content, a direct recruitment campaign, and an innovative way for the Australian Navy to find its new intelligence recruits.