If you work with a healthcare professional such as an audiologist, they’ll give you a full audiogram, or hearing test, which provides concrete information about your level of hearing loss.
They can also explain the differences between hearing aid styles and make a recommendation about which style might be best for you.
Audiologists may not offer the same variety of brands and styles that you might get from an online retailer.
If you purchase hearing aids through an online retailer, you may have the option of taking an online hearing test. These tests may be accurate, but they may not be as comprehensive or personalized as some people would like.