Analytic study of the Tadoma method: identification of consonants and vowels by an experienced Tadoma user.

Performance on identifying consonant and vowel stimuli through the Tadoma methods of speechreading was studied for a deaf-blind, experienced user of Tadoma. For a set of 24 consonants in CV syllables, performance averaged 55%. For a set of 15 vowels and diphthongs in CVC syllables, performance averaged 56%. Confusion matrices derived from the identification tests were analyzed for performance on a set of articulatory/phonological features, the results of the feature analysis for consonants indicated that the features voicing, lip rounding frication, and place were well-perceived; for vowels, and features lip rounding, tenseness, and vertical lip separation were well-perceived.