This project aims to develop and validate tests for evaluating functional performance of hearing-impaired individuals using auditory processing tasks. Many of the measurements used in the clinical setting under well-controlled conditions do not accurately reflect the difficulty that individuals with hearing impairment experience in the real world, and these limitations extend as well to soldiers returning from service duty who acquire hearing impairment and/or traumatic brain injury. In collaboration with colleagues at Walter Reed Military Medical Center, we are conducting a series of speech recognition and speech comprehension tasks in noise that vary the cognitive effort of the listening task, either by adding a memory component (auditory 1-back task), varying the linguistic cues in the speech signal, or increasing the speed of signal presentation. Tests will be validated on normal hearing control subjects and hearing-impaired subjects. We will also evaluate hearing aid algorithms to determine their efficacy for improving functional hearing performance in hearing impaired soldiers.