This is a complex one, which gives hearing aids an unfair stigma. The primary reason many individuals fail to wear hearing aids comes down to 2 key reasons - first-time users who prematurely discontinue hearing aid usage due to adapation problems, along with hearing expectations not matching chosen hearing aids.
In relation adaptation problems, this poses a problem more frequently in people who have left treatment of hearing loss too late in life. In these people, problems are usually overcome, however, they do have more issues and require stricter, regular hearing aid use that the average hearing aid user. With this in mind, if motivation isn't there for these people, they will stop wearing them. This is only overcome through regulary daily use, which allows the brain to correctly go through the adaptation process that comes with neuroplasticity. In audiology we call this the "acclimatation period". During the acclimatation period, the person may find certain sounds (particularly high-frequency sounds) overwhelmingly loud and intrusive, expressing "these hearing aids are just too tinny" or "they simply don't sound right" or "all I hear is noise".
Alternatively, other common reasons for non-use is when people do not match hearing expectations with hearing aid technology purchases. For example, if people expect to only hear better in one-on-one situations and follow dialogue on the TV more easily, they do not require high-end technology hearing aids. However, if people expect to hear well at restaurants, cafes, and business meetings, they will require higher levels. For this reason, it's important to ensure hearing expectations match hearing aid budgets.
In summary, by selecting the appropriate hearing aids tailored to your hearing needs, and consistently using them from the outset, these challenges are nearly always be overcome.