Binaural Interference: a Guide for Audiologists

Book excerpt: Binaural interference occurs when the speech input to one ear interferes with the input to the other ear during binaural stimulation. The first published study on binaural interference twenty-five years ago demonstrated that some individuals, particularly older individuals, perform more poorly with two hearing aids than with one and/or more poorly with binaural than monaural stimulation on electrophysiologic as well as behavioral measures. Binaural interference is relevant to every audiologist because it impacts the successful use of binaural hearing aids and may explain communicative difficulty in noise or other challenging listening situations in persons with normal-hearing sensitivity as well as persons with hearing loss. This exciting new book written by two highly respected audiologists first traces the history of its study by researchers, then reviews the evidence, both direct and indirect, supporting its reality. This is followed by a discussion of the possible causes of the phenomenon and in-depth analysis of illustrative cases. The authors outline a systematic approach to the clinical detection, evaluation and amelioration of individuals who exhibit binaural interference. Suggestions are furnished on improved techniques for evaluation of the binaural advantage in general and on sensitized detection of the disorder in particular. The book ends with recommendations for future directions. Given the adverse impact of binaural interference on auditory function and its occurrence in a significant subset of the population with hearing loss, as well as in some individuals with normal-hearing sensitivity, research on binaural interference only recently has begun to flourish, and adaptation of audiologic clinical practice to identify, assess, and manage individuals with binaural interference has yet to become widespread. The authors intend for the book to provide impetus for pursuing further research and to encourage audiologists to explore the possibility of binaural interference when patient complaints suggest it and when performing audiologic evaluations. The book is intended for practicing clinical audiologists, audiology students, and hearing scientists.