Role of speech audiometry of pilots with hearing loss in evaluating their eligibility to obtain a civil aviation medical certificate (CMA): a case report

Abstract

Hearing assessment of pilots is performed annually to obtain the aeronautical medical certificate (CMA). Many pilots have hearing loss, mainly caused by exposure to noise and presbycusis. Audiometric criteria for obtaining CMA is advocated by the Brazilian Civil Aviation Regulation (RBAC), and when they do not reach the thresholds, a test is given to assess if the pilot can hear the voice of the examiner at normal intensity in a quiet room at 2 meters and facing in the opposite direction of the sound source. However this test does not evaluate the ability of discrimination of the pilot. Objectives: To discuss and propose the use of speech audiometry as the test of choice in the evaluation of civil pilots who did not fulfill the minimum requirements in the tone audiometry as recommended by RBAC. Case report: a case was evaluated of a pilot who did not fulfill the audiometric criteria recommended by RBAC. He was then asked to listen to the voice of the examiner at 2 meters distance when facing backwards, whereupon the results were inconclusive, and he was then sent to undergo speech audiometry, which gave abnormal results. Discussion: A proper evaluation of hearing of the civil pilot is highly important in order not to put his or his crew’s life at risk. When the pilot does not fulfill the criteria of pure tone audiometry, it is proposed that a hearing test be performed at 2 meters distance from the examiner and while facing backwards. However this test does not evaluate the ability of discrimination of what is spoken. The test does not establish exactly how the response of the pilot should be evaluated and what should be spoken. Thus, it is proposed the speech audiometry with auditory discrimination (speech discrimination) be the test of choice for evaluation of the pilots who do not meet the audiometric criteria of RBAC. This test is easily reproducible and can be performed at the same location as audiometry, and uses phonetically balanced words already established in Portuguese. Conclusion: In the evaluation of pilots with hearing loss in the tone audiometry greater than that advocated by RBAC, it is very important to use a test that assesses the ability to discriminate words and is easily reproducible. The easiest test to reproduce, which assesses auditory discrimination, is speech audiometry and it should be used whenever a pilot has a hearing loss.