Normative study: High frequency hearing tresholds (9-20kHz) in normal-hearing patients in between the ages of 8 and 23 years and 11 months old, from Chillan city

Abstract

Introduction: There are several studies showing that high frequency audiometry serves the important purpose in hearing loss early detection; nonetheless, Chile does not have a standard regulation for clinical implementation of the previously mentioned exam. Aim: To standardize high frequency thresholds (9-20) in patients with normal hea- ring in between the ages of 8 and 23 years and 11 months old from Chillan city. Material and method: Non-experimental, descriptive and held in a transversal lapse of time. 259 normal-hearing subjects were evaluated, belonging to elementary, middle, high school and higher -university- levels of education. All subjects underwent a high- frequency audiometry for which was used a (Gradson Stadler) GSI 61 audiometer, with (Sennheiser) HDA 200 headphones. Results: It was observed that high-frequency thresholds tended to increase their figures according to age and frequency requirements. No meaningful differences -regar- ding male or female subjects- were found, although there were note worthy differences in 9, 10 and 14kHz frequencies. The numbers of the thresholds were presented as per- centiles, considering ‘normal’ those located in between P10 and P75. Conclusion: This regulation can be used as a point of reference for normality in order to early detect subjects having a hearing loss risk, and to also take health-related action suita- ble for each particular case, by using similar equipment to the one described in this study.