April 16th, 2006
This is my dissertation that was completed to fulfill the requirements of my PhD at Northwestern University. The findings informed my later plug-in design work for Hipno, a set of plugins published by Cycling74. The chapter 2 contain a primer on granular methods that many people have told me they found useful. Chapter 3 reviews granular research to date and many of the earlier software that implemented these techniques. Even if you don’t dive into the actual experimental data, these may of interest.
ABSTRACT – Granular processing is a computer music technique that manipulates “grains” of sound to produce a variety of effects. Grains are produced by multiplying short segments of digital audio, typically lasting between 10 and 50 milliseconds, with an amplitude envelope of equivalent length. Software designed to produce granular processing effects often requires the user to manage multiple parameters that lack a clear connection to the audio output. A better understanding of how listeners perceive the processing output should yield insights into how the user interface could be simplified.
A series of three experiments was designed to investigate how listeners perceive differences between granular processing examples. Stimuli were produced using specific program settings to process two distinct sound sources. In each experiment, at least twenty participants were asked to rate the similarity of each possible pair of stimuli including identity pairs that existed among these stimuli. The author then used multidimensional scaling (MDS) to develop a graphical representation of the perceptual organization exhibited by participants.
Differences between stimuli included the processed sound source and settings for the grain duration and grain period parameters. Visual analysis of the MDS solution showed that participants clearly distinguished between the two sound sources. Processing descriptors based primarily on the review of literature were tested for correlation to the MDS dimensions. This analysis revealed the significance of three processing features: (1) a base-2 logarithmic scaling for differences in grain duration, (2) the minimum and maximum boundaries for randomized grain durations, and (3) the mean value and total deviation for randomized grain periods.
Between-subject variables relating to experience with electroacoustic music were also examined. However, the results of this secondary inquiry were deemed inconclusive overall based on the relationship between participants’ responses to pre-experiment questions and a priori operational definitions.
The findings were used to inform the design of a new graphical user interface (GUI) for granular processing. The resulting GUI helped to verify this study’s conclusions by successfully demonstrating their practical application to software development. The GUI features unique controls for managing randomization and a feedback display for monitoring differences between the control input and audio output.
Tags: granular perception, granular toolkit, hipno, phd •
Posted in publications •
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March 26th, 2006
A small collection of externals used for various spectral processing. Includes objects for computing amplitude in decibels and a few complex math functions. Available for Max/MSP 4.x.
Special thanks to f.e chanfrault for the windows port.
Tags: fft •
Posted in code, maxmsp •
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March 24th, 2006
This object implements a constant power panning formula and applies it to any input signal. Panning info can be sent as audio or control data. Uses a lookup table, so it is very efficient. Also included in the granular toolkit.
Tags: cppan •
Posted in code, maxmsp •
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October 10th, 2005
Hipno is collection of over 40 audio plug-ins that is hard to categorize. The individual effects feature granular techniques, spectral manipulations, filters, delays and wild hybrids in between. Additionally it features a truly unique control interface called the Hipnoscope and XML import/export of presets. I worked with Electrotap to develop Hipno and Cycling’74 is handling the distribution and sales of this product. Visit their website to find out more.
Tags: cycling74, electrotap, hipno •
Posted in code •
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September 9th, 2005
“mini-concrète” was composed as an exercise in self-imposed limitations when faced with the myriad possibilities of the modern digital audio software. Only one channel of sound is used making the pacing and ordering of sound events the sole focus of attention. For a composer whose pieces usually focus on the interaction of slowly changing layers, this brief and compact work stands is a stark contrast.
Tags: Faculty Composers Recital •
Posted in sound art •
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February 3rd, 2005
This is an older pre-Universal Binary version of the Granular Toolkit for Mac users out there that may need it.
See these other post for more information about GTK:
Tags: granular toolkit •
Posted in code, maxmsp •
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December 8th, 2003
SCI Newsletter, Issue XXXIV:1.
EXCERPT – The third and final day of concerts for the SCI Region IV conference started after a paper session with an afternoon concert featuring several works for interactive electronics and various forms of new media.
Overall, the pieces and performances of this final conference day were well worth the trip many made to be present. They showed the great variety of musical styles being explored by SCI’s members and reaffirmed the organization’s commitment to ensuring the performance of contemporary music by outstanding musicians at its annual conferences.
Tags: concert review, SCI •
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October 2nd, 2003
ATMI 2003 National Conference in Miami, FL.
Co-authored with Peter V. Swendsen.
EXCERPT – Programs in music technology certainly have individual approaches to teaching their students, emphasizing different aspects of the field in their curriculum. However, the differences are magnified in part by the multiplicity names these departments and research centers use to identify themselves. Names and acronyms such as CCRMA, TIMARA, iEAR and CARTAH come to mind. With their differences in the foreground, it can be difficult to see what they have in common beneath the surface. This paper will examine the differences between specific music technology programs in an attempt to identify the similarities in their approaches to the topic, as well as common issues that face these programs. We will also synthesize our observations about these programs and attempt to develop a theory for comparing these emphases within the field. Based on our findings and conclusions, we will then turn our discussion to how technology can act as a hub for arts pedagogy as a whole and not just music.
One question that we should address before diving into the topic is our motivation as authors and the unique perspective our experience allows us to bring to the topic. We are both, admittedly, young scholars at the beginning of our academic careers. But we are also part of a newer breed of students that have been able to pursue music technology as our subject of primary interest throughout our student careers. We were able to seek degrees up to the PhDs that we currently pursue that fall under the umbrella of music technology, a relatively new phenomenon for our field. It is from this perspective that we present our findings, as students who had to search through the myriad of schools offering programs fairly recently in order to choose the best fit for ourselves. We also present this paper as young academics, finding our way in our chosen field of study, and humbly submit it to those more established in the field in the hopes that it will encourage more dialog on these issues.
Tags: ATMI, Miami, music tech degree •
Posted in presentations •
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July 15th, 2003
SMPC 2003 National Conference @ University of Nevada – Las Vegas.
Co-authors: Gary Kendall and Scott Lipscomb.
EXCERPT -Granular processing of sampled audio signals (Roads 1985; Traux 1987) is a technique that has experienced increased interest in recent years. This processing technique has origins in the work of Dennis Gabor and his concept of the acoustical quanta (Gabor 1947), which was developed in response to perceptual research findings. He asserted that, “it is our most elementary experience that sound has a time pattern as well as a frequency pattern (Gabor 1947, p. 591).” Although several software applications are now widely available for realizing granular processing effects (Roads and Alexander 1997; Behles, Starke and Roebel 1998; van der Schoot 1999; Rolfe and Keller 2000), these programs have done little to clarify the perceptual connection between interface controls and audio output, a problem that has persisted since the first computer implementation was reported twenty-five years ago (Roads 1978). A better understanding of how the audio output is perceived is a necessary precursor to the development of a simplified interface that would require the computer “to interpret how to approximate a desired result” (Roads 2001a, p. 27).
In order to further this goal of understanding the perception of granular processing better, the author has conducted a series of three experiments based on models found within studies of musical timbre (Grey 1977; Wessel 1979; Kendall and Carterette 1991; Iverson and Krumhansl 1993). These studies have employed a method of exploring the topic using a similarity-scaling task. Subjects would listen to a series of pairs of sounds, rating the similarity of each pair member to the other while moving through all possible couplings of the stimuli. These similarity ratings were then averaged together and used as the basis for formulating a multi-dimensional scaling solution (Shepard 1962a, 1962b; Kruskal 1964a, 1964b). MDS uses these similarity ratings to produce a graphic representation of the relationships that exist within that data. Stimuli that are viewed as similar will be placed in close proximity to one another, while those viewed as dissimilar will be have a greater distances between them. The differences are represented in a single graphic plot of points representing the stimuli used. This seemed like an appropriate method to employ in our study, however we must emphasize that we are not attempting to draw connections between the results of our study and those found in timbre research. Our comparison is simply with their experimental methods.
Tags: granular perception, Las Vegas, SMPC •
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July 9th, 2003
Journal SEAMUS, Volume XVI:2, pp. 34-46.
ABSTRACT – Since the generation of granular textures was first automated using a computer (Roads 1978), granular synthesis has grown to become a popular tool for creating new sounds in electro-acoustic music. Many effects can be achieved through the granulation of sampled sound including time compression (Jones and Parks 1988) and expansion (Truax 1990) independent of pitch alterations. Such effects can be created using Cycling74’s Max/MSP software, allowing them to be utilized in real-time. However, the software does not include sufficient externals to meet the efficiency and flexibility needs for creating such effects. This paper details a collection of externals and abstractions for Max/MSP that the author has created with the aim of meeting these needs.
Tags: granular toolkit •
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