After de vision, hearing is the second most important sensorial mechanism to get information during the operation of an aircraft. It allows pilots to perceive, process, and identify sounds from the surrounding environment. It is key to hear well both in flight and on the ground, especially between 500 and 3000 Hz for the proper reception of spoken language and auditory signals.Objective: Determine the progressive changes through time and hearing frequencies that affect the audiometric measurements on military pilots of military forces in years 2009, 2010 and 2011.Material and Methods: This is a longitudinal cohort study in which it will be identified the audiometric behavior on the population of military pilots of Colombia in 2009, 2010 and 2011. It will make a retrospective review of these audiometries. To archieve this, the population of military pilots were divided in two groups: fixed wing aircraft pilots which correspond to 47, and rotary wing pilots which are 155.Conclusions: It was found that most altered frequency in the total population was 6000 Hz. In fixed wing pilots frequencies affected were 4000 Hz and, 6000 Hz. The most affected frequency in rotary wing pilots were 4000 Hz, 6000 Hz and 8000 Hz, which concludes that exposure affects pilots in high frequencies. A relationship with the number of hours flown and audiometric alterations was found in impaired pilots between 1000 and 4000 hours of flight, at 4000 Hz, 6000 Hz and 8000 Hz and, an alteration at all frequencies in those pilots over 5000 flight hours in 2009, presenting subsequent recovery in next years. This study did not establish the causes of such recoveries.Rotary wing pilots showed a steady increase in all frequencies in comparison to fixed-wing pilots.
