RISK OF HEARING-LOSS CAUSED BY LISTENING TO MUSIC VIA HEADPHONES

Sound levels of music played from mini-cassette players via head-phone s were measured in a nonrepresentative group of 681 pupils whose ages were between 10 to 19 years. Each pupil completed a questionnaire givi ng the total time spent listening to music each day. The pupils set th e music levels (free field corrected short time Leq) between 60 dB(A) and 110 dB(A). In the age group from 12-16 years, 10% chose 110 dB(A). Nearly 50% of the total group usually listened to music less than one hour per day, and just less than 10% listened for four or more hours. The energy equivalent of continuous sound pressure level for an expos ure time of 8 h per day was for 55% Leq sh <66 dB(A) and for 7% Leq 8 h >95 dB(A) while 4% had an Leq 8 h > 105 dB(A). Estimation of the exp ected hearing losses (HL) were based on ISO 1999: about 10% of the tot al group were predicted to have a HL > 10 dB at 4 kHz after 5 years. A fter listening to sound in this manner 0.3% were expected to develop h earing losses at age 25 years that would be severe enough to substanti ally impair speech intelligibility.