Merluzzi F, Arpini A, Camerino D, Barducci M, Marazzi P
Istituto di Medicina del Lavoro, Università degli Studi di Milano.
Med Lav. 1997 May-Jun;88(3):183-95.
The aim of the study was to assess the state of hearing levels in young Italian subjects via an epidemiological study, and also, by means of a questionnaire, to assess the attitude of young people to music, how they listen to music and how they perceive the risk of noise-induced hearing damage. The sample studied consisted of 391 youths undergoing their first medical examination for military service. The hearing threshold was assessed by means of a semiclinical tonal audiometry with sound-proof earphones calibrated to ISO Standard 389 following the method of ISO Standard 6189. At the end of the study 315 youths were judged eligible for the study, 81% of whom lived in the city of Milan. 63% said they went to a discotheque 1-4 times a week and 3% said they listened to music with earphones at maximum volume. These conditions are considered to be potentially dangerous for hearing since among youths leaving discotheques disorders have been observed that are indicative of hearing fatigue: lowering of the hearing level 7%, buzzing in the ears 37%, sense of muffled sound 12%. In the group studied, environmental noise was a factor of disturbance for sleep (13%), for study and reading (43%), listening to the radio, to music and watching TV (29%). Only 7 youths said their hearing was "not normal", but the thresholds were all higher than audiometric zero, which are clearly worse than the values observed in similar studies reported in the literature. This study reports the mean values, SD, minimum and maximum and centile values of the distribution of hearing thresholds, separately for right and left ears. A comparison was made between the hearing in the group least exposed: a significant difference was observed only for the right ear while for the left ear there was only a tendency. The authors conclude that hearing in young people to-day is worse than in the past, whatever be the causes, and that due account should be taken of this state of affairs, by encouraging prevention programmes for noise-induce hearing loss at all levels and on every possible occasion.
