Classification of the severity of acoustic trauma based on pure tone threshold audiometry

A simple-to-use classification system is presented for expressing the hearing loss resulting from acoustic trauma. The system is based upon the implications for social hearing as seen in the pure tone air conduction hearing test, which is classified according to specifically segmented areas of the audiogram. A study of the audiometric results of 102 ex-army men with ACT and 25 controls with normal hearing included a detailed questionnatire to relate the patients' functional complaints to their audiograms, and the clinical picture was then completed by the administration of speech audiometry tests both in quiet and in backgroands of various signal-to-noise ratios. Three main severity categories of hearing impairment were established. These are described and illustrated.