Sonic Husbandry: Hybridising and Morphing Sounds

  • Tutor: Dr Jez Wells
  • Level: C/4 (1st year students), I/5 (2nd year students), H/6 (3rd year students)

Aims and content

A wide range of digital tools for analysis and/or synthesis of audio offer ways of creating and understanding hybrid sounds. Rather than just being a mixture of two or more sounds, a hybrid is a single sound which contains elements or characteristics of its ‘parents’. When the relative contributions of parents changes over time then sounds which dynamically change type, or morph, are created.

This project will look at ways in which such sounds can be imagined, devised and created. To do this we will consider musical sound in two ways: how it is produced and how it is perceived. These ways of understanding sound are often referred to in computer music as physical and spectral models. Working with these models begins with a study of musical acoustics (how musical instruments produce sound) and psychoacoustics (how humans perceive and respond to sound). While no expertise in physics or psychology will be assumed or required beyond a competence in GCSE level maths and science, some time and effort will be required to become familiar and then comfortable with concepts and techniques relating to this kind of sound modelling. With these established, work can then begin with computer-based tools which allow us to find out what different varieties of sounds are made of and how those sounds are produced. Then we will then look at how we can combine different elements to create new hybrid sounds and morph between them. This is how we will navigate and explore ‘timbre space’ (although perhaps the term ‘action/gesture space’ is more appropriate for physical modelling). New sounds may require more than just timbre (or physics) design. For example, inharmonic sounds may require the development of new tuning systems.

Whilst doing this practical work we will also examine some relevant literature in this area: writing that considers the purpose and meaning of these approaches to sound design. Although it will certainly be a main focus, work need not be confined to computer-based sound production. The theories, philosophies and techniques that we will consider might also be applied to finding new ways of playing or combining acoustic instruments.


A set of sound designs with accompanying text of approximately 3000 words. Depending on whether they are intended to be digitally or acoustically generated, the designs should be submitted as either computer (e.g. Max/MSP or Pure Data patches, CSound orchestra file) or human (e.g. score, instrument preparations) instructions. Audio examples should also be provided (either as .wav files on a data disc or tracks on an audio CD). These may be accompanied by a rendering/recording of a short composition which demonstrates how the new sounds might be used.

Reading and listening

  • Wishart, Trevor. Audible Design. York: Orpheus the Pantomime, 1994.
  • Miranda, Eduardo Reck. Computer Sound Design. Oxford: Focal Press, 2002.
  • Hugill, Andrew. The Digital Musician. New York: Routledge, 2008.
  • Pukette, Miller. The Theory and Technique of Electronic Music. Singapore: World Scientific Publishing, 2007.
  • Howard, David M. and Angus, Jamie A.S. Acoustics and Psychoacoustics. Oxford: Focal Press, 2009.
  • Hall, Donald E. Musical Acoustics. Pacific Grove: Brooks/Cole, 2002.
  • Rossing, Thomas et al. The Science of Sound. San Francisco: Addison-Wesley, 2002.          
  • Sethares, William. Tuning, Timbre, Spectrum, Scale. Berlin: Springer-Verlag, 2005.
  • Carlos, Wendy, electronic instruments. The Secrets of Synthesis. Enhanced CD, East Side Digital, ESD 81702, 2003 (reissue of material originally released in 1986).
  • Carlos, Wendy, electronic instruments. Beauty in the Beast. Enhanced CD, East Side Digital, ESD 81552, 2000 (reissue of material originally released in 1986).

(A more complete and up to date list will be provided at the start of the module)

Learning outcomes

By the end of the taught part of the module all students should:

  • know how sound is produced by common types of musical instrument and how it is perceived by humans;
  • understand, and be able to use, computer-based techniques for spectral and physical modelling of sound;
  • be aware of current approaches to sound hybridisation and morphing, as demonstrated in existing musical works and sound design tools and described in the relevant literature;
  • be familiar with the concept of multidimensional spaces (such as timbre space) for designing and describing sound;

First years: On completion of the module, in their independent work, students should demonstrate Learning Outcomes A1-A6

Second years: On completion of the module, in their independent work, students should demonstrate Learning Outcomes B1-B6

Third years: On completion of the module, in their independent work, students should demonstrate Learning Outcomes C1-C6