Many people complain about poor “speech intelligibility.” Can you tell us what may lay behind this complaint for some, is there clinical assessment for it, and what are the implications for hearing aid use?

James W. Hall, III, Ph.D., is Clinical Professor and Associate Chair in the Department of Communicative Disorders at the University of Florida in. His research interests include auditory neurophysiology, auditory processing disorders, tinnitus (and hyperacusis). Among more than 150 publications, Dr. Hall is author of Audiologists’ Desk References and four other books.

This is perhaps best answered by providing some background. As a result of advances in auditory neuroscience, the study of how hearing regions of the brain actually function, as you’ve read earlier in this book, there’s growing awareness that “we hear with our brain, not with our ears.” The practical implication of this statement is clear—hearing assessment of children and adults is not complete until speech perception is evaluated under difficult, yet commonly encountered listening conditions. The ability to hear very faint simple sounds, evaluated with the traditional pure tone audiogram, is an example of a very basic auditory process. The simple hearing test, however, doesn’t provide adequate information about real-world hearing difficulties. Some people with considerable hearing loss, as described by the audiogram, seem to do very well in most listening situations. On the other hand, if the brain is not processing sound well, then even a person with normal hearing sensitivity for faint sounds may experience serious problems with speech perception and understanding, especially in adverse listening environments. A deficit in hearing in a person with a normal audiogram is referred to as a “central auditory processing disorder” (CAPD). The diagnosis of CAPD can be made in persons of all ages. This review focuses on CAPD with adults.

There are different types of hearing problems that a person with CAPD might experience. Auditory processes important in communication that are evaluated in a complete diagnostic assessment for CAPD might include . . .