This study reports the results of a large number of hearing-aid benefit measures obtained from 134 elderly hearing-aid wearers during the first year of hearing-aid usage. Benefit measures were obtained after 1 month, 6 months, and 1 year of hearing-aid use by all participants. In addition, follow-up measurements of hearing-aid benefit were performed on 49 of these same hearing-aid wearers following 2 years of hearing-aid use. All participants in this study were fit binaurally with identical full-concha in-the-ear (ITE) hearing aids that used linear Class-D amplifiers with output-limiting compression. Benefit measures included several objective tests of speech recognition, as well as the subjective self-report scales of the Hearing Aid Performance Inventory (HAPI; B. E. Walden, M. E. Demorest, & E. L. Hepler) and the Hearing Handicap Inventory for the Elderly (HHIE; I. Ventry & B. Weinstein, 1982). Although group means changed only slightly over time for all of the benefit measures, significant differences were observed for some of the benefit measures, especially among the subjective, self-report measures of benefit. In almost all of the cases exhibiting significant changes, performance was significantly worse (less benefit) at both the 6-month and 1-year post-fit interval compared to the measurements at 1 month post-fit. In general, the individual data from the 134 participants who were represented in the 1-year data set were consistent with the trends in the group data described above. Regarding longer term changes in benefit following 2 years of hearing-aid use, minimal changes were again observed. In all, there was little evidence for acclimatization of hearing-aid benefit in this study in either the group or the individual data.