Speech perception deficits in poor readers: a reply to Denenberg's critique

We reply to Denenberg's (1999) recent critique of our work (Mody, Studdert-Kennedy, & Brady, 1997). Denenberg mounted two main lines of criticism, one concerning characteristics of the population sampled for the experimental group, and the other a statistical critique, concerning (a) violation of parametric assumptions for use of the F distribution and (b) our supposed acceptance of the null hypothesis of no differences between experimental and control groups. We show that the first criticism stemmed from a misunderstanding of the experimental hypothesis and that the second can be answered by both parametric and nonparametric comparisons across conditions within the experimental group, without reference to the control group. Thus, our original conclusion stands: The difficulty with rapid /ba/-/da/ discrimination that some children with reading impairment may experience does not stem from difficulty in discriminating the rapid spectral transitions at stop-vowel syllable onsets.