February is over, and that means RPM 2013 is, too. I only managed three tracks, but at least I did spend some good time thinking about sound.

My tracks are here.

For some reason, I've had trouble generating csound soundtracks to accompany video I've made with Processing. I decided to look into it again tonight, and...I can't seem to repeat the problem. It appears to work fine.

Here, the balls make some noise when they overlap, and a different kind of sound when they hit the sides of the frame.

Click to embiggen on Flickr.

I had to get cardioverted today (i.e., I was "shocked" at the ER to get me out of atrial fibrillation into normal "sinus" rhythm). I got a copy of the EKG strip which showed the two shocks, and I made a sound file from it:

sound from EKG by Matthew M. Conroy

I scanned the copy of the strip, then wrote a Processing sketch to create a Csound score from it and then created the sound file with Csound.

Track five is up at RPM 2011. It is called "Pride and Enjoyment" from the sample I used as the source audio. I used Csound to generate many layers of rhythms made from sub-samples of one main sample. I threw some ring modulation in the middle to make things more crunchy.

Two new tracks up at the RPM 2011 Challenge.

One is straight noise created from the first 100,000 zeros of the Riemann Zeta Function.

Another is one result of an idea I've been using for a while. It is a granular synthesis kind of thing, where the amplitudes of a bunch of grains of fixed frequencies are determined by a quasi-cellular automata. The idea is that the next instant (0.01 seconds) of sound is determined by the current instant of sound.

I hope to do some non-Csound things this month, but time will tell.

I finally got around to creating a page with my noise from integer sequences.

Put your headphones on and check it out and let me know what you think (or hear), and if you have suggestions for other sequences.

Oof. I only got two tracks done for RPM 08. Well, at least I got something done, and I was working on another two or so that just didn't get finished. The tracks are now on my sounds page (these are better quality mp3s than the one on my rpm profile page I linked to earlier).

Another track for my RPM '08 "album" on my profile there.

This is 100 sinusoidal oscillators with slowly, linearly changing frequencies, all spread across the stereo image. Kinda fun, I think.

For years I've wanted to try the "quadrafuzz" idea out in Csound. The Quadrafuzz is a device by Craig Anderton that splits the input signal into four bands, distorts each one, and mixed the four bands back together. This is very easily done in Csound, though here I've used pure clipping for the distortion, which some may find a bit "harsh". This example mp3 is the result of processing a sample of a "clean" electric guitar with this Csound instrument. Here are the orchestra and the score files.

The output of a pure clipping fuzz is a rectangular wave. The "quadrafuzz" output looks like a skyline, like this:

I've wanted for some time to make a simple "robot voice" vocoder effect in Csound. This mp3 contains an original sample, followed by a 40-band sine wave vocoded version, then a 40-band sawtooth wave version, then a 10-band sine wave version, an upside-down version and then a 40-band filtered noise version. The key to all of this is Csound's balance opcode. Here are the Csound orchestra and score files.

The output bands are split to the left and right channels, so though the original sample is mono, the output is quite stereo.

Much of the guts for this orchestra file were copied from a more general-purpose Csound vocoder example at www.thumbuki.com.