For an FAA medical certification (First, Second, or Third Class), the standard distance for the conversational voice test is 6 feet. During this hearing exam, the applicant must demonstrate the ability to hear and understand an "average conversational voice" in a quiet room using both ears simultaneously. To ensure the pilot is not lip-reading, they are required to stand with their back turned to the examiner. If the applicant can correctly repeat words or numbers spoken by the Aviation Medical Examiner (AME) at this distance, they pass the hearing portion of the physical. If a pilot fails this initial 6-foot test, they are not necessarily disqualified; they must then undergo more formal "audiometric" testing using a calibrated machine. This secondary test measures thresholds across various frequencies (500Hz to 3000Hz), and if the pilot still fails, they may be required to wear a hearing aid or undergo a "Medical Flight Test" to prove they can safely hear radio communications and cockpit warnings while in the air.