ABSTRACT
Objective To study extended high frequency (EHF) audiometry for early detection of hearing loss in student pilots in civil aviation.Methods A total of 175 student pilots (all male,18~25 years old, mean 20.2±0.92 years) from a university flight academy were surveyed and underwent EHFA.All subjects had hearing thresholds ≤25 dB HL at conventional frequencies (0.25~8 kHz).The results were compared with the corresponding recommended standards in other countries.According to the use of personal listening devices, all the subjects were divided into the low risk group (non-use, 121 cases) and the high risk group (using>1 year, day>1 hour, 52 cases).The differences of hearing thresholds and detection rates at EHF between the two groups were compared.Results The hearing thresholds of 173 subjects (1 case of middle ear disease and 1 case with family history of hearing loss were excluded) at 9~20 kHz were slightly higher than the reference equivalent threshold sound pressure level (RETSPL) prescribed by American National Standardization Association and the age-matched thresholds recommended by a foreign literature (P<0.05 or P<0.01).The hearing thresholds in the high risk group elevated dramatically than that in the low risk group at 9,12.5,16 and 18 kHz(P<0.05 or P<0.01).As frequencies increased, the detection rate of hearing thresholds in the high risk group decreased gradually, and at 18 and 20 kHz it was significantly lower than that in the low risk group (P<0.01).Conclusion EHF audiometry is a helpful tool for early detection of noise-induced hearing loss in student pilots.Hearing health care should be emphasized in civilian student pilots.It is recommended to avoid the use of personal listening devices or reduce the use time of them.
ABSTRACT
Objective To evaluate the medical indexes for student pilots from different areas , to discover the major different indexes between different areas ,and to establish the space distribution model of military pilots .Methods A cross-section survey was conducted among student pilots , and 290 student pilots sampled as respondents were interviewed with questionnaires and subjected to a physical examination , involving distant vision , heart function , and pulmonary function , before a database was established , cleaned and analyzed by EpiData 3.02, SAS 9.13 with double checking .Results There was no difference between the medical indexes of student pilots from 7 areas, but the psychological selection performance record and the entrance examination record were different .Student pilots from area E had the highest psychological selection performance record while those from area D had the highest entrance examination record .Conclusion Student pilots have area difference ,so we should pay close attention to their birth place during recruitment of student pilots .