Conservation of hearing.
D006309:Hearing; D006311:Hearing Disorders / Q000517:prevention & control*; D006317:Hearing Loss, Noise-Induced / Q000517:prevention & control; D006320:Hearing Tests / Q000592:standards; D006801:Humans; D008403:Mass Screening; D009622:Noise; D009784:Occupational Diseases / Q000517:prevention & control; D010033:Otitis Media / Q000175:diagnosis; D014942:Workers' Compensation