Katherine Morton and Mark Tatham

FRONT PAGE

CONTACTS

Dynamic Force of the Cyclist, ca. 1914 by Umberto Boccioni [1882-1916], from the collection of the University of Michigan Museum of Art. Lithograph: h. 29.5cm, w. 38.4cm.

[key words: 'speech production', 'speech perception', phonology, prosodics, phonetics, 'cognitive phonetics', acoustics, linguistics, expression]

RESEARCH INTEREST

I am basically interested in how speakers formulate plans for what they want to say, and how listeners work these out from the waveforms produced by speakers. The research area therefore covers the theory of both speech production and speech perception, and focuses on the development of plausible models which help elucidate and explain speech as a key human behaviour. These models must be testable, and to this end I have tried to concentrate on fully explicit computational models which can be experimented with to see if they are capable of adequately simulating aspects of speech production and perception. Current work focuses on characterising some aspects of prosody - especially rhythm and intonation; cognitive management of phonetic processes; mapping the relationship between production and perception processes and the acoustic signal; how speakers communicate expressive content and how listeners perceive it.

RESEARCH HISTORY

1. My EARLY work tried to cast some light on speech motor control using the then new experimental techniques of electromyography and air pressure detection and measurement. The data and conclusions from these experiments fed into theoretical considerations of the relationship between phonological objects and processes and their phonetic correlates. The experimental paradigm adopted was essentially the 'physical correlates' paradigm which seeks to set up formal relationships between abstract characterisations and physical measurements. Many of the early publications have been re-issued in web format.
    
2. I developed the Theory of Cognitive Phonetics in the late 1970s and early 1980s. This arose from a clear gap in the theory. The 1960s had seen the development of Coarticulation Theory, and indeed Kate and I played a role in its development, but the theory was too keen to stress how the continuousness of articulation and its subsequent aerodynamics and acoustics were explained by simple physical inertial and other effects. There was clearly an additional factor entering into phonetics: cognitively sourced control exercised over these physical effects. This cognitive intervention was different in type from phonological processes, and merited an explanation within phonetic theory. Cognitive Phonetic Theory included characterisations of the appropriate motor control mechanisms which would permit cognitive intervention in otherwise mechanically dominated (involuntary) physical processes.
    
3. A refinement of Cognitive Phonetics was introduced in the 1990s: cognitive intervention was refined to include a characterisation of the monitoring and supervision of phonetic processes. Phonetic rendering of phonological plans was now seen as a managed process, not a process started and left to its own devices. Phonetics, hitherto considered automatic, is seen as having an active element acting both managerially and as a means of stabilising production processes. Management is carried out by the Cognitive Phonetic Agent. These ideas have been extended our current paper:

• Tatham, M. and Morton, K. (2003 forthcoming) Data structures in speech production. Journal of the International Phonetics Association 33:1.

4. From the late 1980s for a decade I was involved in the development of SPRUCE - a computational implementation of much of the phonetic theory Kate and I had developed earlier. The implementation was expressly designed to test our models, and to that end has proved highly successful. The development of SPRUCE was a joint project with Eric Lewis in the Computer Science Department at the University of Bristol. This decade saw a large number of publications in the area of computational modelling of speech production processes.
    
5. Recently, with Katherine Morton, I have turned again to concentrate more on the development of theory. Our current (post 1997) publications reflect this as well as bringing out more of the substantive detail of the SPRUCE project following the release of the IPR by Essex University in 1998. Kate and I have two books in preparation which focus on an account of how speech communicates expression - especially emotional content. Kate's bio-psychology background was fundamental in initiating this work, and we have now incorporated this into our general cognitive theory. Key publications here are the 2003 JIPA paper which concentrates on an XML formalism for data structures in phonetics, the 2004 OUP book on expression in natural and synthetic speech, and the 2005 Wiley book on our development of high-level synthesis.

Those who know me know of my enduring obsession with high speed road cycling. This image by Umberto Boccioni says it all.