One US teenager out of five has suffered a partial hearing loss, and the trend is constantly growing. According to a study conducted by the Brigham and Women’s Hospital staff on teens age 12-19. Their hearing loss, albeit minor, has increased in percentage for the period 1988-94 vs. 2005-2006, going from 15 to 19,5% of the population. In absolute numbers, some 6,5 million kids have somewhat compromised their hearing. The experts suggest lowering the MP3 players’ volume.