"Measurements on the intensity and the frequency distribution of industrial noises and the hearing losses of industrial workers show: (a) some degree of correlation between the avg. noise level and the temporary and permanent hearing losses; (b) an almost complete localization of the permanent hearing loss in the region above 1500 cycles (with a maximum at 6000 cycles), while the most important components of industrial noises are practically always below this frequency-limit; (c) some correlation between the amount of temporary and permanent hearing losses for high frequencies; (d) a very small permanent hearing loss for low frequencies with a very rapid recuperation from temporary loss in this region.".