Effects of presentation rate and divided attention on auditory comprehension in children with an acquired language...

We examined why auditory comprehension in language-disordered children improves when the rate of presentation of speech is slowed. Seven children with an acquired language disorder associated with a convulsive disorder participated in two divided-attention tasks in which pairs of sentences were presented simultaneously. Subjects were instructed to respond first to the sentence produced by a male speaker (primary sentence) and then to the sentence produced by a female speaker (secondary sentence). In the first condition, both sentences were presented at a normal rate of speech. In the second condition, primary sentences were time expanded 75%, and secondary sentences were presented at a normal rate. We hypothesized that when the primary sentences were presented slowly, spare attention would be available for processing the secondary sentences. Results showed that slowing the presentation rate of the primary sentences significantly improved performance on the secondary sentences, even though secondary sentences were presented at a normal rate of speech. Hypotheses of generally slowed processing of auditory information in language-disordered individuals cannot account for these results. They are consistent, however, with a model of defective attention allocation.