"Sound Advice on Hearing Aids" is a May 1998 factsheet that was written by the Bureau of Consumer Protection within the Office of Consumer and Business Education of the U.S. Federal Trade Commission (FTC). A downloadable version of the factsheet in PDF format is available. The bureau provides information about how a hearing aid works, and outlines the causes of hearing loss. Guidelines for purchasing a hearing aid and details about federal standards for hearing aids are available. The bureau presents the factsheet online as part of FTC Facts for Consumers.