Loss of hearing due to acoustic trauma has been established as a clinical entity. It has also been established that no known form of therapy can improve this type of hearing defect. After rest has removed what fatigue factor existed, the remaining damage may be considered permanent. With this in mind, it is clear that energy must be directed toward the prevention of deafness in persons not yet affected and the arrest of progress in those who have already suffered some loss.
The simplest means of decreasing the intensity of sound reaching the ear has always been the plugging of the external auditory canal. Chippendale,1 in 1866, suggested the use of cotton. Cousins2 recommended the use of ear plugs made of india rubber. During the first World War it was found that cotton soaked in glycerin afforded the best protection.3 This soaking of the cotton in some viscous substance is
WILSON WH. PREVENTION OF TRAUMATIC DEAFNESSA PRELIMINARY REPORT. Arch Otolaryngol. 1943;37(6):757–767. doi:10.1001/archotol.1943.00670030772001