Abstract
This tutorial will help clinicians understand the components of a hearing impairment assessment and rating it in accordance with the AMA Guides to the Evaluation of Permanent Impairment, Fourth Edition, particularly Chapter 9. A hearing impairment evaluation is derived from a pure-tone audiogram and is always based on the functioning of both ears, even if hearing loss is apparent in only one ear. Hearing can be temporarily impaired by recent exposure to loud noise, and an audiogram should be conducted only after an extended period of rest (eg, 12 to 14 hours) after any exposure to loud noises. Audiometers must be properly calibrated and typically measure the decibel loss at 500, 1000, 20000, and 3000 Hz (the test frequencies), the frequencies that represent everyday auditory stimuli. The following steps can be used to determine hearing impairment: 1) test each ear separately using the test frequencies; 2) total the hearing threshold decibel levels of the test frequencies for each ear to determine the decibel sum of hearing threshold levels; 3) use Table 1 to determine a monaural hearing impairment based on the totals calculated in step 2; 4) use Table 2 to calculate the binaural hearing impairment; 5) use Table 3 to convert the binaural hearing loss impairment to whole person impairment. Examples demonstrate the steps and calculations.
