The Aging Auditory System: Considerations for Rehabilitation

An international conference organized by the National Center for Rehabilitative Auditory Research (NCRAR) was held on September 22 and 23, 2005 in Portland, Oregon, to report on the most recent research in auditory aging and to provide a forum for discussion of this information and its role in auditory rehabilitation for the older clinical population. The keynote speaker for this timely topic was Dr. Moe Bergman, whose vast experience and enthusiasm for this area of research set the tone for the 2-day conference. Dr. Bergman, Emeritus Professor of Medicine at the Sackler School of Medicine at Tel-Aviv University, emphasized the increase in the number of the “oldest old” in our population who remain active and contributing members of society and among whom he proudly counts himself. He reminded researchers in the area of auditory aging that this age group may have particular needs for auditory rehabilitation and training and should be included in all aspects of auditory aging research.

The goal of the conference was to demonstrate the contributions of current research to the clinical arena, and the foundation for the overall topic was laid by Dr. John H. Mills, Professor and Vice Chair, Department of Otolaryngology, Medical University of South Carolina, who provided recent insights into the “Pathophysiology of the Aging Auditory System.” This topic sparked a lively roundtable discussion, which included cochlear potentials and otoacoustic emissions and how age-related changes at the level of the cochlea can affect speech perception.

This topic was followed in the afternoon by a session entitled “Behavioral Studies of Auditory Aging.” Dr. James Jerger, Distinguished Scholar-in-Residence in the School of Behavioral and Brain Sciences at the University of Texas at Dallas, contrasted two research approaches in this area: one using group comparisons and the other focusing on individual performance highlighting individual differences that may affect group outcomes. He was followed by Dr. Sandra Gordon-Salant, Department of Hearing and Speech Sciences at the University of Maryland and Director of the Doctoral Program in Clinical Audiology, who focused on temporal auditory processing changes that accompany aging and the effects of these changes on speech recognition in older listeners.

The third session concerned “Cognitive Components of Auditory Aging.” This topic was first addressed by Dr. Arthur Wingfield, Director of the Volen National Center for Complex Systems at Brandeis University, who discussed how limitations in working memory may constrain certain linguistic processes that are necessary to understand speech and that can exacerbate the effects of sensory deficits on speech understanding. Dr. Kathleen Pichora-Fuller, Department of Psychology at the University of Toronto at Mississauga, then described how effortful listening can negatively affect some of the cognitive functions that are involved in speech perception and showed the importance of rehabilitative training in maximizing brain plasticity.

The final session of the conference was aimed at treatment options and was entitled “Amplification and Beyond: Issues Associated with Treating the Geriatric Patient.” Dr. Pamela Souza from the University of Washington in Seattle focused on how temporal speech cues may be affected by hearing aid compression parameters and the effect of these temporal changes in the speech signal on older listeners' ability to benefit from processed speech produced by complex signal processing in modern hearing aids. The final speaker of the conference was Dr. Therese Walden, Chief of Audiology at Walter Reed Army Medical Center in Washington, DC. Dr. Walden presented case studies to illustrate the effects of aging on the choices of techniques and treatments to be used with the older clinical population.

This NCRAR conference demonstrated that there is a need for effective rehabilitation methods designed specifically for treatment of the multifaceted effects of aging on auditory functions, such as cochlear changes, auditory processing limitations, and cognitive effects. These methods may incorporate training programs that target brain plasticity using listening strategies and cognitive processing aids as well as assistive and amplification devices that can be tailored to address individual processing limitations and enhancement of the speech signal for improved audibility. As Dr. Bergman points out in his keynote address, it is especially important to help maintain the ability of the aging segment of our population to remain interested, active, and productive members of society.