Hearing loss in the elderly is the most common type of hearing impairment. The term presbyacusis has been used to describe this category of hearing loss when there are no other etiological factors. However, the term is not precise, because any of several locations along the auditory pathway may be involved to produce the symptoms. The diagnosis is based more on the course of the hearing loss and the associated biological signs of aging than on specific criteria. The loss of speech-understanding ability is one of the most important indicators for a therapeutic intervention, which generally aims at amplification using a personal hearing aid. An improvement in speech-understanding ability with a hearing aid depends on several complex factors, and there is a large amount of intersubject variability in the benefit derived from amplification, even when the magnitude of the hearing loss is comparable. The aim of research on presbyacusis over the next several years--keeping in mind the demographic development in the industrialized countries--will be to further the differential analysis of the factors contributing to auditory communication disorders in the aging population.