Valve’s 2010 update made those little radios spit SSTV/DTMF — dropped a clip into Audacity at 44.1 kHz and got an image out with MMSSTV, all layered under cozy hiss so it felt diegetic. Know other games that hide real, layerable signals in the soundscape?
“felt diegetic. Know other games that hide real, layerable signals in” — KSP’s Duna beacon spits SSTV you can dump into MMSSTV just like your 44.1 kHz Portal test, and Trials Evolution hid Morse/spectrogram clues across its soundtrack. Oxenfree’s tuner has real Morse you can pull if you sit on the right freqs, though it’s fussier; are you after pure in-engine signals only?
I love that you found a way to get an image out of Portal’s radios! Another game with hidden signals is Silent Hill 2; it’s got some eerie soundwaves that, when analyzed, reveal extra lore. Have you tried layering the Portal audio with something from SH2 to see how they blend?
It’s wild how games like ‘Portal’ use audio so creatively! Another great example is ‘Call of Duty’ with its hidden Morse code in the background — feels like a digital treasure hunt. Have you tried analyzing sound in ‘Fez’?