Analysis of Distortion Product Otoacoustic Emission in Pilots Under Physical Examination for Modification to Equipment of High Performance Aircraft / 听力学及言语疾病杂志

ABSTRACT

Objective To evaluate the hearing function of pilots under physical examination for modification to equipment of high performance aircraft,using pure tone audiometry(PTA) and distortion product otoacoustic emission(DPOAE).Methods Analyzed were all the results of PTA and DPOAE of 75 pilots (150 ears) which accepted physical examination for modification to equipment of high performance aircraft in our department from March 2008 to February 2009.75 cases were divided into two groups according to their flight time.The difference between these two groups was studied.Results According to the Equipments of Physical Constitution for Flying Persons of Air force,PLA,all 75 pilots passed the ENT assessments as being qualified for flying.Of all 150 ears,abnormal DPOAEs were obviously higher than that of abnormal PTA tests.128 ears had normal PTA results.92 ears had normal DPOAE results.36 ears (27.6&) showed abnormal DPOAEs at one or more frequencies,especially at 1,3 and 4 kHz.22 ears had abnormal PTA results.20 ears had noticeable V or U shaped thresholds at 3 kHz and/or 4 kHz.The DPOAE amplitudes showed similar curves.The other two ears showed depressions at all frequencies,in both PTA and DPOAE tests.No statistically significant difference was found between the two groups in DPOAE.But statistical difference was found in DPOAE at 4 kHz compared with other frequencies.No statistically significant differences were found between the two groups in DPOAE amplitudes at 1,2,3 and 4 kHz.but at 6 and 8 kHz.Conclusion The application of DPOAE test helped find pilots who were on the early stage of noise-induced hearing loss.These pilots were the most important objects for us to follow up.