To be covered by social security, the hearing aid must be sold with a follow-up service over time, which must be performed by the audioprosthesist who sold the hearing aid. According to a 2015 study by UFC Que Choisir (available here, in french), these services - which represent 40% of the total cost of hearing aids - are rarely used by people who have been fitted with hearing aids, because they have no use for them, they do not wear their hearing aids or because the hearing aid specialist has closed store. In 2017, a american double-blind, placebo-controlled clinical trial (available here) concluded that these expensive services do not generate more satisfaction in the handling, wearing and use of the hearing aid compared to a hearing aid sold without additional services (preset hearing aids such as AZUR and ORISON). These services generate, on the other hand, a consequent refusal from the people concerned, because of their expensive cost. In France, only 1 out of 4 presbyacusic people are fitted with a hearing aid. And, among those who are fitted, it is considered - a taboo figure - that 15% of them do not wear their hearing equipment. In march 2020, with the COVID-19 crisis, the execution of these services became more complex, in particular with the closing of many shops and the application of barrier gestures.