The effects of aging on binaural and spatial hearing

As the size of the older adult population continues to grow, so too does the need to better understand the complex effects of aging on everyday listening tasks involving binaural and spatial hearing. It is well known that older individuals with and without hearing loss often complain of difficulty hearing and understanding speech. In this article the results of recent studies evaluating the effects of aging on various binaural and spatial tasks are summarized and discussed, and an attempt is made to identify the difficulties encountered in daily living by older adults because of problems processing binaural and spatial information. The results of most of the studies reviewed here indicate that the ability of older listeners to localize sound sources, to obtain a gain in speech intelligibility in noise when speech and noise sources are separated, to improve the detection of signals in noise by using binaural cues (as measured with a masking level difference task), and to discriminate interaural differences in time and intensity decline with increasing age. These decreases in performance on binaural and spatial tasks are generally observed even when the effects of hearing loss are taken into account.