THE TIME-COURSE OF HEARING-AID BENEFIT

Objective: The present study sought to determine whether benefit deriv ed from hearing aid use increases with hearing aid experience, This qu estion is of considerable interest to both researchers and clinicians. Several previous investigations recently published have obtained mixe d results, Design: Control conditions were provided to address the pot ential influences of practice effects and changes in preferred hearing aid gain, The experimental group consisted of 13 hearing-im paired li steners about to be fit with their first hearing aid, The control grou p consisted of 13 hearing aid users with at least 1 yr's experience wi th their hearing aids. The control group permitted examination of prac tice effects that may have confounded previous results showing increas es in benefit with experience, Hearing aid benefit was defined as aide d speech recognition ability minus unaided speech recognition ability and was assessed repeatedly over 18 wk, Two measures of hearing aid be nefit were employed: an objective syllable recognition task and a subj ective questionnaire, For the objective measure, hearing aid benefit w as assessed for the condition of fixed hearing aid gain and also for t he condition of subject-adjusted hearing aid gain to examine effects o f changes in audibility that may have influenced benefit and confounde d previous results, Results: The objective measure of group mean heari ng aid benefit increased significantly over time for both gain conditi ons for the new hearing aid users, but did not increase for the long-s tanding control group, Subjective benefit increased over time, but wit hout statistical significance for the new hearing aid users, and was e ssentially unchanged for the long-standing control group, Conclusions: Results suggest that the observed improvements in speech recognition are not due to increases in audibility nor to simple practice effects, The overall improvements in benefit over time were of statistical sig nificance and also practical importance for studies of group differenc es. However, the improvements are too small to be observed consistentl y for individual hearing aid users.