Hearing impairment rating determination is described in the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Sixth Edition, Section 11.2a, Criteria for Rating Impairment Due to Hearing Loss. A hearing impairment evaluation for adults who have acquired language skills is derived from a pure-tone audiogram and always is based on the functioning of both ears even though hearing loss may be present in only one ear. Audiometers should be properly calibrated, and technicians should be appropriately trained to obtain accurate measurements. Audiograms typically are obtained at four frequencies (test frequencies): 500, 1000, 2000, and 3000 Hz, which are considered to be representative of everyday auditory speech ranges. The evaluator tests the individual's right and left ears at the test frequencies and adds the decibel levels for each of these frequencies for each ear separately; consults Table 11-2, Computation of Binaural Hearing Impairment; and finally consults Table 11-3, Relationship of Binaural Hearing Impairment to Impairment of the Whole Person. Tinnitus can be rated if the individual experiences hearing loss in the ear and this loss affects speech discrimination; loss is limited to a maximum of 5% loss. The AMA Guides provides no correction in the hearing section for age-related loss of hearing, although the latter may be apportionable. A table presents a model hearing impairment report.