Once again, here’s the same electric piano from Processing Sound Using Photoshop. This time is has been liquefied by the Photoshop filter of the same name. Liquefy is nice because is relies on the human element of dragging through the image to warp it in the direction the mouse pointer is moved. I purposefully did not liquefy short sections of the waveform so I could compare the original signal and the manipulated one.
Liquified Electric Piano Pattern
The Spherize filter in Photoshop is designed to force an image to bubble outward as if wrapping it around a sphere. Can you imagine what it would sound like to warp audio in the same fashion? I imagined that that the frequency would warp downward as the waveform was stretched and then back up to the original pitch on the opposite side.
Well, that’s almost exactly what happened, although I didn’t expect it to sound as deep and eerie as it does. For this entry I have shortened the image horizontally to emphasize what the filter actually did. I also lightened the image to make it more visible. It looks a bit like a zeppelin whereas the original image of the sound was flat. Please enjoy the Spherized version of the loop from the last entry.
Spherize Electric Piano Pattern
I made this recording half way across the Central Avenue bridge from Northeast Minneapolis, to the downtown area. This bridge crosses the Mississippi, which was virtually frozen over except for water flowing rapidly over stages of a lock and dam system.
Huge formations of ice were hanging over the falls collecting on logs caught in the flow. The stereo image of the recording consists of the raging river below on the left hand side and sparse traffic on the right. I used the built in mics on the PCM-D50 covered up with a nice fuzzy wind screen like a winter hat.
Central Avenue Bridge Recording
The Arduino is a little programmable doo-hickie that can be used for lots of things. I was playing with mine recently and hooked the digital outs up to an analog sound board. This is a common thing to do with the Arduino. You can coax the thing into making analog-like sounds through the digital output. Since it is digital, everything is a square wave.
All of these sounds were made with a little routine I got from the sample code for making a sound:
void playTone(int tone, int duration) {
for (long i = 0; i < duration * 1000L; i += tone * 2) {
digitalWrite(speakerPin, HIGH);
delayMicroseconds(tone);
digitalWrite(speakerPin, LOW);
delayMicroseconds(tone);
}
}
Here are a few little audio samples that I made tonight whilst fooling around. The first one is just random frequencies:
long i = 0; i= random(5, 100); playTone( i*i, 100 );
Arduino Random
The rest are just a sweep using different durations:
for(int i = 5; i < 100; ++i ) {
playTone( i*i, 50 );
}
for(int i = 100; i >= 5; --i ) {
playTone( i*i, 50 );
}
Arduino Sweep Slow
Arduino Sweep Medium
Arduino Sweep Fast
Arduino Sweep Very Fast
It has digital and analog inputs as well, so my next goal is to use some sort of control voltage to make noises. More to come!
M.
Here’s another example of audio that was recorded for the purpose of live looping during a performance.
The clip is dated from August 18, 2006 and is a typical example of how I often use a resonant drone with cutoff frequency manipulation through delay to create textures.
Resonant Drone