In the future, the rehabilitation of adults with hearing loss is likely to involve modern information technology. It is therefore important to determine whether and to what extent adults with hearing losses use the internet. When evaluating hearing rehabilitation, it is reasonable to use self-report questionnaires as outcome measures. The questionnaires used in audiological research are developed and validated for paper-and-pencil administration. Standardized questionnaires used in the audiological context should also be evaluated in an online administration format. Using the internet in the audiological rehabilitation process might be a cost-effective way to include additional rehabilitation components by guiding hearing-aid users on topics such as communication strategies, hearing tactics and how to handle hearing aids. The development of online rehabilitation programs might foster behavioral changes that will positively affect hearing-aid users.Four studies were conducted with a total of 338 participating hearing-aid users. In the first study, the participants' amount of internet use was investigated. In the second study, the administration format (online vs. paper-and-pencil) of four standardized questionnaires used in hearing research and clinics were evaluated. Finally, two randomized controlled trials were performed to evaluate the efficacy of an online rehabilitation program that included professional guidance by an audiologist. The program lasted over five weeks and was designed for adult, experienced hearing-aid users. The effects of the online programs were compared with the effects of a control group. In the first randomized controlled trial, the participants of the control group participated in an online discussion forum without any professional contact (Study III). In the second randomized controlled trial, the control group participants were informed that the rehabilitation program was full and they were transferred to a waiting list pending treatment (Study IV).The results in the first study showed that 60% of the participating hearing-aid users used computers and the internet. The internet use level was at least at the same level for people with hearing loss as for the general age-matched population in Sweden. In the second study a significant main effect of questionnaire format was found for one questionnaire, which evaluated the participants' activity limitations and participation restrictions; the participants had higher scores on the online format than on the paper format. Other than that, no interaction effects for format were found for the other three questionnaires. In the first randomized controlled trial, after the five-week online rehabilitation program, both groups of participants showed significant improvements and the effects were maintained in domains of activity limitation and participation restriction at the six-month follow-up. Moreover, effects in psychosocial domains were found. In the second randomized controlled trial, after the five-week online rehabilitation, the p...