An assessment of hearing status among 120 patients who underwent audiometric testing at their initial examination reveals that thirty-three (27.5 per cent) had normal hearing, whereas 57 (47.5 per cent) had conductive hearing loss. 29 (24.2 per cent)mixed loss and only one (0.8 per cent) pure sensorineural loss. The mean conductive loss in the speech frequencies (500~2 000 Hz) was 10.3 dB. The maximal air-bone gap was 35 dB. The mean conductive hearing loss associated with perforations, occupying one-half or more of the eardrum area, was two fold higher than that associated with smaller perforations. It is noteworthy that in spite of the direct correlation between the size of the perforation and the extent of the air bone gap, there were two patients with large perforations whose audiograms showed normal hearing. Patients whose injury occurred in water had a larger conductive hearing loss than others. Moreover, water sports injuries have a greater proportion of large perforations, yet statistical analysis confirms that the magnitude of conductive hearing loss is linked more to the size of perforation than to the cause of injury.

It has been established that in 29 out of 30 patients with a sensorineural hearing loss a conductive element was also present, while only one had a pure sensorineural hearing loss. Furthermore, approximately one fourth of the patients with non-explosive blast injury of the ear, suffered from sensorineural hearing loss irrespective of the mechanisms of trauma. Most patients with this type of injury had a high frequency loss, whereas impairment of bone conduction in the speech frequencies was demonstrated in only three cases. Three patterns of sensorineural hearing loss were identified. The first was characterized by a dip that involved a hearing loss in one frequency: a dip at 4 000 Hz in four patients and at 8 000Hz in six. The second showed ab normality of bone conduction in severat adjacent high frequencies: 18 patients had different combinations of hearing loss. The third pattern of sensorineural hearing loss appeared as separate dips. There were two patients in this category, the first had one at 1000 Hz and another at 4000 Hz, while the second had dips at 3000 Hz and 8000 Hz.

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