Archive for March 17th, 2008
Sound analysis
I have been using Aleksander Refsum Jensenius’s max/msp sound analysis software to analyze digital and analogue signals that I have recorded with my detectors. When I see the sound rendered from different perspectives – loudness (spectral energy), brightness (spectral centroid), noisiness (spectral flatness), sonogram, pitch (estimated), onsets and as musical notation – in this way, I get to know more about the character of each of the various field recordings. The screenshot below is one moment of detecting the electromagnetic activity when I make a call on my mobile phone.
From this exercise I hope to glean some ideas about how to treat the data that will come in from the fountain’s detectors, and how this will control the various water valves of the fountain.
The digital signals are on-off and squirty – like premature ejaculations, while the anaolg signals are continuous and surgey and can be more kind of slowly orgasmic. What I am currently thinking of is passing each peak of the digital signals sequential to the small valves close to the circumference of the fountain bowl. As the peaks happen so fast, I figure that this is the best way of signal distribution – it allows for time for the mechanics of the each of the valves to respond before getting new input. Right now it seems like either the pitch or noisiness signal analysis methods would be the most useful way of controlling the valves. Pitch/peak opens a valve and sends a water jet into the air, the height controlled by its value, and then the valve closes fast to get a “drop”.
If you want to try this out, download the sound of my mobile (unedited from dv cassette/7.89mb) and then open/run it in Aleksander’s sound analysis patch. There’s a osx stand alone version, (1.6mb), so you don’t need to have max/msp installed on your mac.