Pea whistle steganography

I can't remember how I first came across these near-ultrasonic 'beacons' ubiquitous in PA systems. I might have been scrolling through the audio spectrum while waiting for the underground train; or it might have been the screeching 'tinnitus-like' sensation I would often get near the loudspeakers at a local shopping centre. Whatever the case, I...

Steamboat Willie (1928) was one of the earliest cartoons with synchronized sound. That is, it had post-production sound effects; this was something new and exciting. Now that the cartoon has recently entered the public domain[bbc24] we can safely delve into its famous soundtrack. See, there's something interesting about how it sounds... If you...

This story, too, begins with noise. I was browsing the radio waves with a software radio, looking for mysteries to accompany my ginger tea. I had started to notice a wide-band spiky signal on a number of frequencies that only seemed to appear indoors. Some sort of interference from electronic devices, probably. Spoiler alert, it eventually led me...

I've been experimenting with methods for visualising harmony, intonation (tuning), and overtones in music. Ordinary spectrograms aren't very well suited for that as the harmonic relations are not intuitively visible. Let's see what could be done about this. I'll try to sprinkle the text with Wikipedia links in order to immerse (nerd snipe?) the...

I had a dream one night where a blackbird was talking in human language. When I woke up there was actually a blackbird singing outside the window. Its inflections were curiously speech-like. The dreaming mind only needed to imagine a bunch of additional harmonics to form phonemes and words. One was left wondering if speech could be transformed...