Original Article DOI 10.3349/ymj.2009.50.6.771 pISSN: 0513-5796, eISSN: 1976-2437 Yonsei Med J 50(6): 771-776, 2009 Hearing Threshold of Korean Adolescents Associated with the Use of Personal Music Players Myung Gu Kim,1* Seok Min Hong,2* Hyun Joon Shim,3 Young Doe Kim,4 Chang Il Cha,2 and Seung Geun Yeo2 1Department of Otolaryngology, Masan Samsung Hospital, School of Medicine, Sungkyunkwan University, Masan; 2Department of Otorhinolaryngology and Head & Neck Surgery, College of Medicine, KyungHee University, Seoul; 3Department of Otorhinolaryngology and Head & Neck Surgery, School of Medicine, Eulji University, Seoul; 4Bio ENT Clinics, Gwangju, Korea. Purpose: Hearing loss can lead to a number of disabilities and can reduce quality of life. Noise-induced hearing losses have become more common among adolescents due to increased exposure to personal music players. We, therefore, investigated the use of personal music player among Korean adolescents and the relationship between hearing threshold and usage pattern of portable music players. Materials and Methods: A total of 490 adolescents were interviewed personally regarding their use of portable music players, including the time and type of player and the type of headphone used. Pure tone audiometry was performed in each subject. Results: Of the 490 subjects, 462 (94.3%) used personal music players and most of them have used the personal music player for 1-3 hours per day during 1-3 years. The most common type of portable music player was the MP3 player, and the most common type of headphone was the earphone (insert type). Significant elevations of hearing threshold were observed in males, in adolescents who had used portable music players for over 5 years, for those over 15 years in cumulative period and in those who had used earphones. Conclusion: Portable music players can have a deleterious effect on hearing threshold in adolescents. To preserve hearing, adolescents should avoid using portable music players for long periods of time and should avoid using earphones. Key Words: Hearing loss, adolescent Received July 29, 2008 Revised: February 21, 2009 Accepted: February 21, 2009 Corresponding author: Dr. Seung Geun Yeo, Department of Otorhinolaryngology and Head & Neck Surgery, College of Medicine, KyungHee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-702, Korea. Tel: 82-2-958-8474, Fax: 82-2-958-8470 E-mail: yeo2park@yahoo.co.kr *These authors contributed equally to this work. ∙Current address: Seok Min Hong, Department of Otorhinolaryngology-Head & Neck Surgery, Chuncheon Sacred Heart Hospital, Hallym University College of Medicine, Chuncheon, Korea. ∙The authors have no financial conflicts of interest. © Copyright: Yonsei University College of Medicine 2009 INTRODUCTION Noise-induced hearing loss (NIHL) is a public health problem that can limit usual daily activities. Hearing loss can reduce physical and social execution behavior status and may induce psychological symptoms of anxiety and depression.1,2 Much effort has, therefore, been made to reduce the incidence of hearing loss in adults who are exposed to occupational noises. The incidence of NIHL has also been increasing in children and juveniles. For example, 40% of students between the ages of 16 and 25 years have audiological evidence of NIHL,3 and 1% of children attending school were reported to have symptoms of NIHL in 1996.4 More recently, 12.5% of students between the ages of 6 to 19 years were found to have noise-induced threshold shifts.5 NIHL in children and juveniles is related to noises produced during recreational and leisure activities. The noises produced by toys, band activities, motor sports and loud noises in concert halls and nightclubs have harmful effects on hearing.6,7 The use of personal music players can also cause noise-induced hearing loss in juveniles.7,8 Personal music players have very strong sound tones, and their maxi- mum volume level can reach 78-136 dB.7 At present, most Korean students have Yonsei Med J http://www.eymj.org Volume 50 Number 6 December 2009 771