Of course, he's just reporting the facts

William Clark runs the audiology department at Washington University medical school and, being an academic, publishes in the hearing journals. He seems to have specialized in determining whether hearing loss is a function of one's occupation. Specifically, he has published studies of firefighters, trainmen and miners. In each case he has concluded that any hearing loss incurred by workers in these fields was not due to equipment manufactured by companies who paid him to do the studies. Maybe he was being impartial, but clearly his results are tainted.