4. As regards the representativeness of the study population for
the general population it has to be taken into consideration
whether only healthy, adult male workers were investigated.
In contrast, the authors noted that the study results themselves
were not influenced to any major extent by a possible healthy
worker effect because a pre-selection with respect to hearing
function for the high and low exposure groups can hardly be
assumed. In addition, such an effect can hardly be assumed
for the small hearing deficits found in this study that will not
be noticed in daily life.