Date of Award

Spring 2012

Document Type


Degree Name

Doctor of Philosophy (PhD)


Communication Disorders & Special Education


Special Education

Committee Director

Anastasia M. Raymer

Committee Member

Ivan Ash

Committee Member

Silvana M. Watson


Auditory processing of speech is influenced by internal (i.e., attention, working memory) and external factors (i.e., background noise, visual information). This study examined the interplay among these factors in individuals with and without ADHD. All participants completed a listening in noise task, two working memory capacity tasks, and two short-term memory tasks. The listening in noise task had both an auditory and an audiovisual condition. Participants included 38 young adults between the ages of 18-35 without ADHD and 25 young adults between the ages of 18-35 with ADHD. Results indicated that diagnosis, modality, and signal-to-noise ratio all have a main effect on a person's ability to process speech in noise. In addition, the interaction between the diagnosis of ADHD, the presence of visual cues, and the level of noise had an effect on a person's ability to process speech in noise. In fact, young adults with ADHD benefit less from visual information during noise than young adults without ADHD, an effect influenced by working memory abilities. These speech processing results are discussed in relation to theoretical models of stochastic resonance and working memory capacity. Implications for speech-language pathologists and educators are also discussed.