Relationship between leisure noise exposure and otoacoustic emissions in a young Asian population.

OBJECTIVE: This study compared the otoacoustic emissions amplitudes of Asian youths at risk of leisure noise exposure through the use of portable music players with their less exposed counterparts. DESIGN: A listening habit survey was conducted. Subjects were divided into two groups for analysis. A subject was placed within the high risk group if he/she reported listening to music at near maximum volume and had a physical measurement of his/her preferred listening level recorded at > 85 dBA. DPOAE and TEOAE levels were measured and compared between the two groups. STUDY SAMPLE: A total of 1928 students from a tertiary educational institution in Singapore. RESULTS: TEOAE levels were found to be significantly lower in the high risk group at 4 kHz. DPOAE levels were also found to be significantly depressed in the high risk group at 1, 2, 3, and 4 kHz with the largest mean difference at 4 kHz. A four-way ANOVA carried out for OAE amplitudes using gender, ear laterality, risk profile, and years of usage as independent factors also showed that risk profile was a significant factor in determining the OAE amplitude at 4 kHz. CONCLUSION: We have demonstrated that both DPAOE and TEOAE values are diminished in the Asian subjects at high risk for noise exposure.

The music listening preferences and habits of youths in Singapore and its relation to leisure noise-induced hearing loss.

INTRODUCTION: Noise-induced hearing loss (NIHL) is a preventable condition, and much has been done to protect workers from it. However, thus far, little attention has been given to leisure NIHL. The purpose of this study is to determine the possible music listening preferences and habits among young people in Singapore that may put them at risk of developing leisure NIHL. METHODS: In our study, the proportion of participants exposed to > 85 dBA for eight hours a day (time-weighted average) was calculated by taking into account the daily number of hours spent listening to music and by determining the average sound pressure level at which music was listened to. RESULTS: A total of 1,928 students were recruited from Temasek Polytechnic, Singapore. Of which, 16.4% of participants listened to portable music players with a time-weighted average of > 85 dBA for 8 hours. On average, we found that male students were more likely to listen to music at louder volumes than female students (p < 0.001). We also found that the Malay students in our study listened to louder music than the Chinese students (p < 0.001). CONCLUSION: We found that up to one in six young persons in Singapore is at risk of developing leisure NIHL from music delivered via earphones. As additional risks due to exposure to leisure noise from other sources was not taken into account, the extent of the problem of leisure NIHL may be even greater. There is a compelling need for an effective leisure noise prevention program among young people in Singapore.