|This article relies largely or entirely upon a single source. (August 2010)|
A custom-made artificial palate is moulded to fit against a speaker's hard palate. The artificial palate contains electrodes exposed to the lingual surface. When contact occurs between the tongue surface and any of the electrodes, particularly between the lateral margins of the tongue and the borders of the hard palate, electronic signals are sent to an external processing unit. EPG provides dynamic real-time visual feedback of the location and timing of tongue contacts with the hard palate.
This procedure can record details of tongue activity during speech. It can provide direct articulatory information that children can use in therapy to monitor and improve their articulation patterns. Visual feedback is very important in the success of treating deaf children.
History of Electropalatography
Electropalatography was originally conceptualized and developed as a tool for phonetics research to improve upon traditional palatography methods. Both military and academic language researchers used early electropalatography tools to obtain accurate information regarding tongue-to-palate contact in a number of foreign languages.
Early EPG devices used direct current electricity to power the sensors, which were activated by moisture sensors on mouthpieces. Mouthpieces originally closely resembled modern dental impression plates. Mouthpieces became more customized over time, which allowed for more accurate research.
EPG added significant insight into academic understanding of articulatory phonetics. In the 1960's and 1970's a number of independent individuals and companies recognized EPG's potential for pedagogical and therapeutic applications. Despite the multiple attempts to reverse engineer EPG tools for speech therapy, most companies failed to commercialize EPG effectively. EPG tools remain fairly expensive tools for speech therapy and phonetics research, though the information they provide are difficult to obtain using other methods of visual feedback of articulation.
Two primary manufacturers of EPG tools exist: CompleteSpeech in the United States,and Articulate Technologies in Great Britain. Completespeech is a private company that specializes in speech therapy oriented EPG tools, branded as The SmartPalate System. The SmartPalate System uses a standard size sensor sheet with 126 sensors that is fitted to individual mouthpiece molds. Articulate technologies provides both speech therapy and research oriented EPG mouthpieces, branded as The Reading Palate and The Articulate Palate. Articulate technologies EPG sensors are places by hand for individual users' mouthpieces.
Effectiveness in Therapy
Electropalatography has been studied in a variety of populations, including children with cleft palate, children with Down syndrome, children who are deaf, children with cochlear implants, children with cerebral palsy and adults with Parkinson's disease. Therapy has proved to be successful in tested populations. Longitudinal studies with large sample sizes are needed to determine the long-term success of therapy.
- Zanuy, Marcos Faúndez (2005). Nonlinear analyses and algorithms for speech processing: International Conference on Non-Linear Speech Processing, NOLISP 2005, Barcelona, Spain, April 19–22, 2005 : revised selected papers. Springer Science & Business. p. 186. ISBN 3-540-31257-9.
- Articulate Technologies. http://www.articulateinstruments.com/a-history-of-epg/. Missing or empty
- Plauche, Tanner. "What is SmartPalate". CompleteSpeech. Retrieved 2014-05-13.
- Hardcastle, William. Articulate Technologies http://www.articulateinstruments.com/wordpress/wp-content/uploads/2013/08/Information-for-making-plaster-impressions-4.pdf. Retrieved 2014-05-13. Missing or empty