순음청력검사는 음차에서 발생되는 것과 같은 순음을 전기적으로 발생시켜 각 주파수에 따라 음의 강도를 조절하여 청력역치를 측정하는 방법이며 청력을 나타내는 기본적인 검사 방법으로 크게 기도전도검사와 골도전도검사로 나눌 수 있다. 그 중 골도전도검사는 내이의 반응을 직접 검사함으로 기도전도검사에서 얻어진 난청의 원인이 중이 이전에 있는지 내이 이후에 있는지를 확인하여 전음성과 감각신경성 난청을 감별하고 진단하여 치료대책을 수립하는 지표가 되는 검사로써 청력검사의 기초적 방법이다. 골도전도검사에서는 기도 전도검사에 쓰이는 헤드폰과는 달리 골도전도검사용 진동자를 사용하여 검사를 하게 되는데 진동자를 통해 발생된 소리는 유모세포의 자극을 직접 유발시키게 되며 그 전달경로는 크게 세 가지로 분류할 수 있다.7) 첫째 두개골의 진동은 내이에서도 동일하게 일어나며 이러한 측두골의 진동이 전정계
This study was explored utilizing both forehead and mastoid positions of bone oscillators in order to verify the clinical effectiveness on positions of bone oscillators. Sixty adults, 20 (40 ears) with normal hearing, 20 (40 ears) with conductive hearing loss and 20 (40 ears) with sensorineural hearing loss participated in the study. Pure tone audiometry was performed with air conduction (AC), bone conduction at mastoid (BCm), and bone conduction at forehead (BCf) thresholds. The results of this study were as follows： 1) Comparison among transducers, the thresholds of AC, BCm and BCf, showed statistical significance at three groups. 2) The threshold difference of three transducers in three groups showed statistical significance except AC-BCf of normal hearing and sensorineural hearing loss groups. 3) The threshold difference of BCf-BCm at normal hearing, conductive hearing loss, and sensorineural hearing loss groups were 10.1, 7.4, 7.4 dB, respectively. 4) Considering the lowest threshold at BCm, less BCf-BCm threshold difference in conductive hearing loss and frequency characteristics of BCf-BCm threshold difference, the forehead position is less influenced by osseotympanic bone conduction and inertial bone conduction than the mastoid position. It seems that forehead placement is more suitable for inner ear measurement than mastoid placement. However, the data in this study are limited in providing the standardized force for the forehead measurement and more data should be collected for better understanding of bone conduction mechanism. KEY WORDS：Bone conduction·Forehead·Mastoid.
INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION AND CONCLUSION REFERENCES
