Vowel Perception and Production in Adolescents with Reading Disabilities

Perception and production of the vowels /I/, /ε/, /æ/ in the words pit, pet and pat were investigated in two groups of adolescents who differed significantly on measures of reading and phonological awareness. Perception performance was assessed using slope measurements between vowel categories. Duration measurements and a rating system based on first and second formant (F1 and F2) values were used to analyze production performance. As a group, the students with reading disabilities not only perceived but also produced less well-defined vowel categories than the control group of age-matched good readers. Perception and production performance, however, were not correlated. Results suggest that the speech processing difficulties of the students with reading disabilities include weak phonological coding for vowel sounds with similar phonetic characteristics. The implications of these findings for intervention are addressed.