disley.org: music technology

This page is a collection of Alastair Disley's research into music technology, including his current and previous work. Some of the PD (Pure Data) patches created alongside this research can be found here, including a PD drawbar organ simulator.

current research: synthesis control for musicians

I'm currently working on a project to look at better ways of controlling synthesis for musicians. Traditional synthesisers, whether analogue or digital, have controls for such things as waveforms and filters that are often non-intuitive for musicians. We are developing a prototype synthesiser which a musician should be able to operate intuitively. Initial research has concentrated on studying what terms musicians use to describe timbre, and the relationships between timbral adjectives and acoustical features of musical stimuli. The synthesis method is hybrid sampling/additive synthesis, and has been implemented in PureData (PD).

I work on this as part of the Audio Lab of the University of York Department of Electronics with David Howard and Andy Hunt. The project is EPSRC funded and will conclude in 2007.

Publications relating to this work include:

• Musicians' use of timbral adjectives, Disley, AC, Howard, DM, and Hunt, AD, Proceedings of the Institute of Acoustics, Vol 28, Part 1, 2006, pp670-679. Not available online.
• Spectral correlation of timbral adjectives used by musicians, Disley, AC, Howard, DM, and Hunt, AD, The Journal of the Acoustical Society of America, May 2006, Volume 119, Issue 5, p3333, abstract and conference presentation. Abstract available online here.
• Music Synthesis for the Terrified: Using Everyday Words to Control Synthesizers by Alastair Disley, David Howard, and Andy Hunt. An invited lay language version of the paper immediately above, available here on the ASA website only.
• Timbral description of musical instruments, Disley, AC, Howard, DM, and Hunt, AD, Proceedings of the 9th International Conference on Music Perception and Cognition, 2006. Download the paper here or browse the abstracts here and the proceedings here.
• Further spectral correlations of timbral adjectives used by musicians, Disley, AC, Howard, DM, and Hunt, AD, The Journal of the Acoustical Society of America, November 2006, abstract and conference presentation. Abstract available online here.
• Implementing synthesis control using timbral adjectives, Disley, AC, Howard, DM, and Hunt, AD, The Journal of the Acoustical Society of America, May 2007, Volume 121, Issue 5, p3119, abstract and conference presentation.
• Towards a music synthesizer controlled by timbral adjectives, Howard, DM, Disley, AC, and Hunt, AD, Proceedings of the Fourteenth International Congress on Sound and Vibration, July 2007, Australian Acoustical Society.

We have also taken the opportunity provided by this research to examine whether psychoacoustic tests can be conducted reliably over the Internet rather than the traditional controlled in-person method. Initial results are promising, and were presented here:

• Remote psychoacoustic testing using the Internet, Disley, AC, Howard, DM, and Hunt, AD, The Journal of the Acoustical Society of America, November 2006, abstract and conference poster. Abstract available online here and poster available online here.

current research: listener identification of pipe organ stops

The significance of various factors, such as onset transients, in listener identification of pipe organ stops has often been assumed. I have been exploring a number of those factors, and my findings to date have been presented as follows:

• Onset transient significance in listener identification of pipe organ stops, Disley, AC, and Howard, DM, The Journal of the Acoustical Society of America, May 2006, Volume 119, Issue 5, p3333, abstract and conference presentation. Abstract available online here.
• The significance of relative loudness in listener identification of pipe organ stops, Disley, AC, and Howard, DM, The Journal of the Acoustical Society of America, November 2006, abstract and conference presentation. Abstract available online here.
• The significance of offset transients in listener identification of pipe organ stops, Disley, AC, and Howard, DM, The Journal of the Acoustical Society of America, May 2007, Volume 121, Issue 5, p3199, abstract and conference poster.

This research is unfunded.

previous research: listener perception of pipe organs

My PhD was the conclusion of work I had begun as an undergraduate, looking at how listeners perceived and described the many different sounds a pipe organ can make. I discovered that certain timbral adjectives (bright, clear, flutey, thin and warm) were commonly understood by a group of English speaking listeners. There are of course many limits to the circumstances in which this holds true, but it's difficult to condense a 300 page thesis into one sentence! One interesting factor was the way in which British and American English speakers differed in their understandings of some timbral adjectives. I published several papers on my work, the most recent of which includes the most significant results from my thesis. Please note that contact details in these papers may be out of date - for current details, see the contact information page.

• Spectral correlates of timbral semantics relating to the pipe organ, Disley, AC and Howard, DM, Proceedings of the Baltic-Nordic Acoustics Meeting, 2004. Download the paper here or view all the conference papers here.
• Spectral correlates of timbral semantics relating to the pipe organ, (additional publication of the same paper) Disley, AC and Howard, DM, Quarterly Progress and Status Report, vol 46, KTH Stockholm Department of Speech, Music and Hearing. Download the paper here or view recent years of the publication online here.
• Timbral Semantics and the Pipe Organ, Disley, AC and Howard, DM, Proceedings of the Stockholm Music Acoustics Conference, 2003. Download this paper only here or the entire proceedings from the Abstracts and Proceedings link here.
• My PhD thesis is titled An exploration of timbral semantics related to the pipe organ, Disley, AC, The University of York, 2004. It is not available online, but a copy resides in the University of York library and microfilm copies should be available via inter-library loans in most countries.

I also used the opportunities presented by my PhD experiments to study how listeners reacted to organs based on their appearance as well as sound. Here I found that an impressive case could improve a listener's verdict on the sound, but a very obvious difference between casework and tonal style generally resulted in a negative impression. This work was difficult to quantify scientifically, but I wrote the following article summarising my findings.

• A Case in Point, Disley, AC, The Organ, Issue 325 (August 2003). Download this article here
  (note - published edition had photographs in mono but better resolution, and different page/volume numbers from this initial proof).

previous research: MSc work

I produced the following web pages during my music technology MSc, so while some aspects of them might be out of date and some links might not work, they provide an interesting introduction to some areas of music technology, acoustics and psychoacoustics, and are worth a browse.

• An introduction to music technology
• Auditory streaming
• Human perception of pitch
• Teraping - a pioneering means of interacting with computer games, projecting the gameplay on to the floor between players, who then used floor-pads as controls. A more professional looking implementation of Teraping was later exhibited at the Graves Art Gallery, Sheffield in 2000 under the title "Projected Games" and was extremely popular with visitors.

In 2007 I finally presented a paper based on that last piece of work and other work we have done with MIDICreator over the years:

• Using technology to enable people of all abilities to explore music, Disley, AC, Howard, DM, and Hunt, AD, The Journal of the Acoustical Society of America, May 2007, Volume 121, Issue 5, p3157, abstract and conference presentation.

other publications

I wrote a number of entries for The Organ: An Encyclopedia (ed. Douglas Bush, Routledge 2005/6), ranging from simple definitions such as pipe and stop to complex mechanisms and the history of some English organbuilders. I have written several articles for the quarterly journal The Organ, including a four-part series on the pipe organs of Stockholm (issues 331, 332, 334 and 336), as well as reviews, articles and letters in a variety of magazines and newspapers, most of which I can't recall details of and are unlikely to be of interest to anyone reading this anyway!