It all depends on the kind of hearing loss you have. Also it depends on the severity of your hearing loss. In most cases, if both of your ears experience hearing loss, you will need two hearing aids because two aids provide a more natural signal to the brain. Hearing in both ears also will help you understand speech and locate where the sound is coming from. The best way to find out of course if to talk to an audiologist.
Like prescription classes, you can’t just purchase a hearing aid from the store. You and your audiologist should select a hearing aid that best suits your needs and lifestyle. Hearing aids’ price vary a lot. They can go anywhere from hundreds to several thousand dollars. Inexpensive hearing aids aren’t necessarily bad. The most expensive ones may not even fit your needs.
Keep in mind, that hearing aids are not hearing surgeries, they do not restore your hearing. They help you hear better. So just like glasses, you need time and patience to get used to them to make them work better for you. Check the warranty when you purchase them to get the most out of your hearing aids.
Source: National Institutes of Health