건강한 20대 청년에서 고주파음역의 청각역치

Abstract

Pure-tone threshold testing at the frequency above 8kHz offers special benefits and challenges. The major benifit is based on that cochlear pathology，resulting from ototoxic drugs or noise, may first be seen in thershold change above 8kHz. The major problem is signal calibration. The purpose of the present study is to estimate the high-frequency hearing thresholds of healthy, young, male adults in twenties and to determine its clinical utility and reliability. The auditory thresholds of the thirty medical students were measured at 11 high-frequencies from 10kHz to 20kHz, using a newly developed high-frequency audiometer(Beltone 2000) and Senheiser HD 250 earphones. All subjects were screened at 25dB HL of conventional pure-tone average, and with normal tympanometry and with no history of significant hearing problem or ear diseases. The thirty normal hearing listeners(60 ears) were tested four times in each ear by one examiner. The average thresholds(dB SPL) were 25.44 at 10kHz, 29.83 at 11 kHz, 33.83 at 12kHz, 38. 81 at 13kHz, 44.42 at 14kHz, 58.33 at 15kHz，74.71 at 16kHz, 85.05 at 17kHz, 92.9 at 18kHz, 95.94 at 19kHz, and 104.7 at 20kHz. The standard deviation was from 7.6dB to 14.6dB SPL in the frequency region of 10-14kHz and from 17.7dB to 19.2dB in the frequency region of 15-18kHz while it was below 14dB in the frequency region of 19-20kHz. These normative data of high-frequency thresholds will be useful in assessing the cochlear pathology, as the method make it possible to have early detection of the sensorineural hearing loss related to ototoxic drugs or noise.