If you decide to buy a hearing aid, be wary: Because of the “scientific” nature of the purchase, consumers are often vulnerable to misinformation and bad deals.

An AARP study conducted in Florida revealed many shoddy sales practices. AARP had consumer testers make 169 visits to 23 different hearing-aid dispensers. The study revealed that half of the dispensers failed to follow the state’s minimum hearing evaluation standards before recommending a hearing aid. Of the consumer testers who had not visited a physician prior to their appointment, only 14 percent were advised that it was in their best interest to see a doc before purchasing an aid, despite the federal law requiring that they be so advised. In many instances, sellers recommended hearing aids for people who did not need them; some dispensers recommended aids to as many as 90 percent of the consumer testers.

The AARP Florida study also found many deceptive sales statements. The most common was claiming that a hearing aid would help slow down hearing loss or ear damage. This is a lie: Hearing aids can only make you hear better and have no impact on your natural hearing capacity.

In our own surveys, hearing-aid buyers for the most part rated sellers favorably. But the ratings and comments we received from customers sometimes echoed the problems cited in the AARP study.

To help you get advice you can trust, our Ratings Tables show how area hearing specialists were rated by local consumers. We primarily surveyed Checkbook and Consumer Reports subscribers, but also other randomly selected consumers we invited to participate.

We asked consumers to rate hearing-aid dispensers “inferior,” “adequate,” or “superior” on questions such as “advice on choice and use of products,” “reliability (standing behind products and delivering on time),” and “overall quality.” our Ratings Tables report, for businesses that received at least 10 ratings, the percent of each company’s surveyed customers who rated it “superior” on each question. Click here for further discussion of our customer survey and other methods.

You can make your own judgments about the quality of advice provided by staff of various companies. Do they seem interested in you? Do they ask detailed questions about problems your hearing loss causes and when you would most benefit from hearing aids? Do they thoroughly explain the testing process and their diagnosis? Do they present several options? Do they provide easy-to-understand explanations for any recommendations they make? Are important choices, such as buying one aid versus two, discussed in ways you can understand?

Check hearing care professionals’ training and competence. Be sure they have credentials: a Doctor of Audiology (Au.D.) and/or a Certificate of Clinical Competence in Audiology (CCC-A), or are a Fellow of the American Academy of Audiology (FAAA). If not, look for other evidence of training and several years of experience.

Check the facilities. The room in which a hearing test is administered needs to be quiet. Ask whether the center uses a sound-treated room (good) or professionally installed sound booth (better).

Shop around. Our undercover shoppers got price quotes from area sellers for six different hearing aids, and found tremendous company-to-company price variation for the exact same devices. (See our section "How to Save Money on Hearing Aids" for more information.)