No, unfortunately wearing hearing aids does not slow down hearing loss. Their function is to reduce the impact that hearing loss has on your ability to hear and comprehend the sounds around you.
Perhaps more important, however, is that hearing aids can reduce the effects of hearing loss on your auditory cortex, or the part of your brain that processes the sound you hear. When hearing loss is left untreated for a long period of time, your brain experiences auditory deprivation that can result in permanent loss of function at the brain level which can’t be treated. Essentially, if you’re not exercising the auditory cortex, you can lose some of your ability to process speech and other sounds—even if hearing is restored with hearing aids later on. Even if you only suspect hearing loss, it’s a good idea to get a full hearing examination with a hearing health care professional who can assess your situation and recommend the appropriate treatment as soon as possible.