Speech comprehension training and auditory and cognitive processing in older adults.

To provide a brief history of speech comprehension training systems and an overview of research on auditory and cognitive aging as background to recommendations for future directions for rehabilitation. Two distinct domains were reviewed: one concerning technological and the other concerning psychological aspects of training. Historical trends and advances in these 2 domains were interrelated to highlight converging trends and directions for future practice. Over the last century, technological advances have influenced both the design of hearing aids and training systems. Initially, training focused on children and those with severe loss for whom amplification was insufficient. Now the focus has shifted to older adults with relatively little loss but difficulties listening in noise. Evidence of brain plasticity from auditory and cognitive neuroscience provides new insights into how to facilitate perceptual (re-)learning by older adults. There is a new imperative to complement training to increase bottom-up processing of the signal with more ecologically valid training to boost top-down information processing based on knowledge of language and the world. Advances in digital technologies enable the development of increasingly sophisticated training systems incorporating complex meaningful materials such as music, audiovisual interactive displays, and conversation.