Hearing and loud music exposure in 14-15 years old adolescents.

Adolescent exposure to loud music has become a social and health problem whose study demands a holistic approach. The aims of the current study are: (1) To detect early noise-induced hearing loss among adolescents and establish its relationship with their participation in musical recreational activities and (2) to determine sound immission levels in nightclubs and personal music players (PMPs). The participants consisted in 172 14-15 years old adolescents from a technical high school. Conventional and extended high frequency audiometry, transient evoked otoacoustic emissions and questionnaire on recreational habits were administered. Hearing threshold levels (HTLs) were classified as: normal (Group 1), slightly shifted (Group 2), and significantly shifted (Group 3). The musical general exposure (MGE), from participation in recreational musical activities, was categorized in low, moderate, and high exposure. The results revealed an increase of HTL in Group 2 compared with Group 1 (P < 0.01), in Group 3 compared with Group 2 (P < 0.05) only in extended high frequency range, in Group 3 compared with Group 1 (P < 0.01). Besides, a decrease in mean global amplitude, reproducibility and in frequencies amplitude in Group 2 compared with Group 1 (P < 0.05) and in Group 3 compared with Group 1 (P < 0.05). A significant difference (P < 0.05) was found in Group 1's HTL between low and high exposure, showing higher HTL in high exposure. The sound immission measured in nightclubs (107.8-112.2) dBA and PMPs (82.9-104.6) dBA revealed sound levels risky for hearing health according to exposure times. It demonstrates the need to implement preventive and hearing health promoting actions in adolescents.