A 1999 study of adults showed hearing loss was the fifth most common disability in the US population, and almost 50% of workers in carpentry, plumbing, and mining had hearing impairment. Determining hearing impairment according to the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fifth Edition, Section 11.2a, Criteria for Rating Impairment Due to Hearing Loss, is straightforward, if limited. Examiners should be aware that hearing can be temporarily impaired by recent exposure to loud noise and should test only after an extended period without such exposure. Audiometers should be properly calibrated, and technicians must be appropriately trained to obtain accurate measurements. The evaluator should separately test both of the individual's ears at 500 Hz, 1000 Hz, 2000 Hz, and 3000 Hz (the representative or test frequencies) and then identify the total worst ear decibel level using the AMA Guides Table 11-1 or 11-2. The evaluator can use Tale 11-3 to convert hearing impairment to whole person loss. Tinnitus also can be rated if a hearing loss in that ear affects speech discrimination; in such instances, the tinnitus rating is limited to a 5% loss. The article includes a Hearing Impairment Rating Sheet that can be used to record data from the hearing impairment evaluation.