Room Sounds and Overtones – Chris Beachy
Here is the story of my project...
For my final project, I initially set out with the idea that I wanted to do some kind of performance involving live sound processing. I began experimenting with ChucK's live sound processing capabilities, and with the help of the example documentation online, came up with simple code that takes input through a microphone, processes it in Chuck, and plays it back through an output. This code can be found by clicking on the Delay Processor link.
Using this code made it possible to experiment with feedback loops, since the sound taken in by the microphone will eventually circulate back to the microphone via the speakers, thus creating the loop. I began playing around with these loops in my dorm room, and soon discovered that it was not the initial sounds and frequencies put into the microphone that were perpetuated, but in fact other frequencies entirely, the natural resonant frequencies of the room. I thought this was really cool, especially because the frequencies generated were different for each room I tried. At Blair's suggestion, I checked out Alvin Lucier's piece “I Am Sitting in a Room”, which essentially dealt with the same concept as my project except the frequencies of the room were brought out by recording a voice, playing that recording into the room and recording it again, and again, and again, until all the original frequencies had been replaced by the room's sounds. My “live version” of Lucier's piece brought out the room frequencies out much more quickly, but required a bit of skill to operate properly without blowing anything up.
The first challenge of bringing out the room sounds was to keep the feedback loops under control, which required a steady hand on the volume during the performance. The next challenge was actually bringing out a diverse range of frequencies from the room, which I attempted to do by singing different frequencies into the microphone. This approach sort of worked, though there always seemed to be a very dominant low frequency in the loop no matter how hard I tried to avoid it with my voice. You can hear this low note in my audio recording of my dorm room. However, I was able to generate some very beautiful moments in which a variety of the room's frequencies were all shining through clearly, creating a very ethereal effect. Though unfortunately I did not record it , my final performance in the listening room was one of my best renditions.
The second piece of my project was to create a Random Generator of pitches from the overtone series with ChucK. The generator used a simple characteristic of the overtone series, where each new partial (n) can be determined by multipliyng the last by (n + 1) / n, a property of the overtone series which I discovered by dividing the string on my guitar into successive fractions to bring out different partials . I was able to tie the Overtone Generator back to my original project by using a piece of Ben Holtz's code that found the dominant resonance frequency of a given room. I then passed that frequency to my Overtone Generator. You can hear a mix I did in my dorm room which incorporates both the feedback loops and the Overtone Series random Generator in one piece. The code for the generator is also linked below.
Finally, the last step of my project was to learn how to use the listening room for the final performance, which proved to be a nervewracking experience. Being all alone experimenting with feedback loops in a silent room with immense audio output power and 16 speakers is harrowing, especially when you don't really know how the room works. I do not recommend it. However, after much trial and error, I eventually got the levels right and gave a decent final performance.
The project was definitely a character-building experience, and at times I felt like some kind of mad scientist holed up in a dark room experimenting with the raw sound of rooms that could blow me away in a second if I let them get out of control. Nevertheless, I did achieve some very beautiful moments and am sure there is a safer way to go about live experimentation with feedback loops and room frequencies and plenty of room for improvement/experimentation on my project for those who would like to try. It was a very raw form of experiencing music and natural frequencies, and I recommend you try it! Below is my code, the code I borrowed from Ben, and a brief mix of the sounds of my room. I hope you enjoy!
Overtone Series Random Generator.ck
Ben's Pitch Tracker.ck All Credit for this code goes to Ben Holtz, who is a great guy. He built an autotuner with it and has recently
become T-Pain's greatest rival.