This study describes the benefits of hearing aid (HA) use in a sample of elderly experienced HA users (n = 102, mean age 81.1 years), investigating the role of the age, hearing impairment and cognitive function. The benefit was assessed in aided condition by measuring audiometric outcomes (aided thresholds and speech reception in quiet and in noise) and self-assessed outcomes addressing the disability and the handicap domains of auditory dysfunction. Several cognitive abilities were assessed, including short-term memory, working memory and executive functions. To discover potential latent factors and assess which factors significantly influenced the benefit of HA use, age, hearing impairment, cognitive function, audiometric and self-assessed outcomes were examined with multivariate analysis, followed by correlation and regression analysis. The analysis revealed a significant improvement in aided audiometric outcomes and a decrease in the perceived disability and handicap in the sample population. Multivariate, correlation and regression analyses showed that better aided audiometric outcomes were significantly associated with hearing impairment of lower degree and higher cognitive abilities. Moreover, self-assessed outcomes were significantly associated with audiometric outcomes and hearing impairment: subjects with better audiometric outcomes and lower hearing impairment tend to perceive more benefit in using their HAs. Cognition was only indirectly associated with self-assessed outcomes through its direct correlation with aided audiometric outcomes, meaning that the perceived subjective benefit with HA was not directly associated with better cognitive abilities.