Listeners who prefer monaural to binaural hearing aids. 
Four patients who preferred monaural as compared with binaural amplification were evaluated.  For these patients, audiometric data, recognition performance on a dichotic digit task, and monaural and binaural hearing aid performance using four amplification strategies (National Acoustic Laboratories-Revised, a speech in noise algorithm, multiple-microphone arrays, and frequency modulated [FM]) are described.  The results of dichotic testing using a one-, two-, and three-pair dichotic digit task in free- and directed-recall conditions indicated a left-ear deficit for all subjects that could not be explained by peripheral auditory findings or by a cognitive-based deficit.  The results of soundfield testing using a speech in multitalker babble paradigm indicated that when listening in noise, there was little difference between aided and unaided word-recognition performance, suggesting that the binaural hearing aids originally fit for each patient were not providing substantial benefit when listening in a competing babble background.  Word-recognition performance when aided monaurally in the right ear was superior to performance when aided monaurally in the left ear and when aided binaurally.  The only successful binaural amplification strategy was the FM system.  The results indicate that listeners with an auditory-based deficit in dichotic listening may function better with a monaural hearing aid fitting or with an assistive listening device such as an FM system.  The findings also suggest that a test of dichotic listening is an important component in the evaluation of patients being considered for amplification.