How Do You Hear?
by Dr. Michael Berry, M.D., Federal Air Surgeon
Good hearing, next to good vision, is a critical capability for the aviator to operate in today’s complex airspace. Even a mild hearing loss (HL) can impair communications degrading both the safety and efficiency of the National Airspace System (NAS). The companion article in this issue addresses some of the more common causes of acquired hearing loss and the appropriate prevention/treatment. Not all pilots are born with good hearing and of those who are, not all retain it. This then becomes a regulatory as well as a clinical concern. This article will focus on the evaluation and certification of pilots engaged in aviation activities that require medical certification.
The Aviation Medical Examiner (AME) is usually the first person that a pilot encounters on the path to medical certification. The FAA requires a hearing evaluation at each medical examination, regardless of the class of medical sought. Although a formal audiometric examination is always acceptable, most AMEs opt to utilize a conversational voice test at six feet with the applicant’s back turned. Hearing is tested using both ears and the applicant can use hearing aids for the test. However, if hearing aids are necessary, then the use of these in flight activities will be required and so annotated on the medical certificate with “must use hearing amplification.” Both external hearing aids and cochlear implants are permissible.
Some conditions have HL as a symptom. Pressure equalization (PE) tubes are frequently used to treat fluid behind the eardrum(s), serous otitis media. As long as there are no complications, medical certification is straightforward. Individuals who do not meet standards even with hearing aids can still request a SODA (statement of demonstrated ability) if the HL is stable. A SODA can be issued for static defects, but may require additional evaluations by an otolaryngologist, a medical flight test (MFT), or a review of operational experience. A MFT is used to ensure that even if unable to perceive auditory cues, the applicant can recognize a power loss or engine failure by a change in vibration and/or instrument indications, recognize an impending stall (buffet), or be alert to warning lights (unsafe gear, caution lights, low rotor RPM, etc.). Other conditions associated with progressive HL such as an acoustic neuroma, vertigo, encephalitis, Meniere’s disease, and meningitis may require additional evaluation and specific clearance from the FAA.
On occasion, an aviator will be unable to pass the hearing test with or without a hearing aid, but will report that he/she is able to hear adequately in the cockpit with the use of a headset. If the applicant successfully passes a MFT using a headset, then a medical certificate is possible, but with this limitation.
Good hearing, next to good vision, is a critical capability for the aviator to operate in today’s complex airspace.
Some pilots are unable to pass any of the above tests due to profound or even complete deafness. Medical certification is still possible and pilot certification up to the commercial level is also feasible, but both have restrictions. The limitation, “Not valid for flying where radio use is required,” will be included on both the pilot and medical certificates. Commercial operations that do not require the use of radio communications, such as banner towing, agriculture (spray) operations, or glider towing, are possible. It is currently not feasible to certify a pilot for airline transport privileges if they are completely deaf. However, cochlear implants have brought hearing to thousands who did not benefit from traditional hearing aids and we have certified airline pilots who have cochlear implants.
Other technologies which may be approved include bone anchored hearing aids (BAHA) and implantable hearing aids. Stem cell research is currently not FDA approved or mature enough for favorable aeromedical consideration. On the non-medical side, in-cockpit weather information and digital communications, such as the aircraft communications, addressing, and reporting system (ACARS) provide information visually, reducing the need for oral communications. While currently used to speed and enhance air to ground communications, this technology also holds promise for future expansion of pilot certification for those who are profoundly hearing impaired.