The PronSci approach takes its starting point from the materials and teaching practices that Gattegno worked on between 1955 and his death in 1988. These were part of his Silent Way approach, which covered all aspects of language learning, not just pronunciation.
Gattegno’s insights have been our inspiration ever since we encountered them.
Catford was a teacher of English and then an academic phonetician of worldwide renown. Independently of Gattegno, he recommended an articulatory approach to learning pronunciation based on practical exercises which make students more aware of their potential for producing new sounds.
For any teacher, we would particularly recommend his Practical Introduction to Phonetics, first published in 1988.
Smith was a Danish phoniatrician who took a holistic view of speech production, realising that speech breathing had significant effects on the rest of speech. He developed the Accent Method of speech therapy, which has been further developed by his collaborator Thyme-Frokjaer. The Accent Method includes exercises that develop good accentuation in the speech breathing of clients with disordered speech. We have adapted these for use in teaching English, a stress accent language.
Wells is emeritus Professor of Phonetics at UCL, and the author of the Longman Pronunciation Dictionary of British and American English (3rd edition, 2008). We have taken this as our reference point for the PronSci materials, departing from this source only when pedagogical considerations demand it.
Wood and Esling both developed analyses of vowel production based on articulatory rather than acoustic principles. These have informed the layouts of our Rectangle charts.
(The labels used in the IPA quadrilateral give a misleading impression that it is an articulatory presentation, but in fact it is based on acoustic principles.)