Although contemporary researchers are concerned about overexposure of portable listening devices (PLD) for adolescents and young adults who often prefer listening to music at high levels for a long time, many of these studies have focused on either comparing sound pressure levels of various kinds of earphones or evaluating the recognition of noise-included hearing loss and listening habits through surveys. Further still, current criteria were developed for occupational noise-induced hearing loss, so there are only a few published guidelines for hearing insults due to recreational noise exposure. The present study, therefore, measures actual listening levels and PLD time in college students using a real-time measurement system and applying that gathered scientific data to the internationally recommended noise exposure standards. Thirty-four college students were asked to listen to music similar to their daily lifestyles for 4-weeks. After installing the application, the Google account that linked to the user's mobile phone was logged into the server communication. When a subject listened to music, the average and maximum listening levels and listening time could then be recognized as his or her Google account ID and stored in the database for analysis. User data was measured at 1-s intervals and delivered to the main server system every 5 s. The data were analyzed as LZeq for mean levels and LCpeak for maximum levels, and also for PLD use time. The mean of the preferred listening level was 68-70 dB SPL for 4 weeks with long enough break times. That is, the listening levels of college students were not high enough to induce instant hearing loss when they used PLD. However, there was a large individual difference in the listening levels and use times. When applied to three recommended noise exposure criteria, the number of exceeded subjects also differed from 0 to 56.72% depending on the criterion. We thus suggest that appropriate and standardized criteria for music-induced hearing loss might be proposed for recreational PLD users.
Keywords: digital health; mobile application; music exposure; noise-induced hearing loss; portable listening devices; tracking method.