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Showing posts from November, 2005

Looking at Sound

Lately I've been listening a lot to Kate Bush's album Aerial - beautiful, wonderful stuff. The album cover is interesting too - the 'islands' that are reflected in the water are actually the amplitude envelope of a recording of some birds singing.

This idea of 'looking at sound' in different ways has been something I've really enjoyed exploring over the last several years. To help visualize the harmonics in a piece of music, I wrote a program a while back that analyses the frequency content of a sound waveform and creates a spectrogram (spectrum over time) of it, colour coding the intensity levels of each frequency.

I think I've found the bird song shown on the cover - it's 2:25 from the start of the song 'Aerial'. Here's what its spectrogram looks like:

The parallel contour lines that are stacked one on top of each other are the harmonics of the bird song. (A synthesizer's been added to the recording, which has changed the amplitue…


I've recently become quite fascinated with the mechanics of biological systems - how cells work, genetics, the 3D physicality of nanometer sized organic molecules. There are two amazing videos by a company called Hybrid Medical Animation (their demo reel and Stages of Mitosis) that capture the essence of it beautifully.

I've become especially fascinated with neurobiology. A number of years ago I developed a number of adaptive real-time signal processing algorithms for echo cancellation that used a "stochastic iteration" error estimation and adaptive feedback algorithm similar to the learning algorithms used in Neural Networks, and that's when I first started getting interested in how the brain works. Recent advances in brain imaging and neurobiology have really been amazing, and have shown that the brain is much more than the matrix of adaptive electrical elements I used to conceptualize it as - it's a complex organic, evolving, chemical driven 3D environment …