The DP-gram is not significantly correlated with PTaud and cannot be used as an objective measure of pure-tone thresholds in early NIHL. Medial olivocochlear reflex strength before the beginning of chronic exposure to occupational noise has no relation to individual vulnerability to NIHL. Although TEOAEs changes after 1 year showed high sensitivity in predicting NIHL after 2 years of exposure, they cannot be recommended as an efficient screening tool due to high false-positive rates.

IEDCS related to compressed-air recreational diving is more common than previously thought, and might occur even when no decompression schedule violation took place. Prompt diagnosis leading to the early commencement of hyperbaric oxygen recompression therapy is the key to complete recovery of cochlear and vestibular function.

The presence of air around the pinna and inside the external ear canal did not improve underwater hearing sensitivity or sound localization. These results support the argument that bone conduction plays the main role in underwater hearing.

Our data show that sound conditioning prolongs the latency to oxygen-induced convulsions. This effect was not accompanied by significant changes in whole-brain antioxidant enzyme activity or the magnitude of lipid peroxidation.

The currently recommended examination for diving fitness ascertains middle ear autoinflation ability only under surface pressure conditions. The purpose of our study was to document and quantify middle ear pressure equalization failure during simulated dives among diving candidates who had otherwise met the otologic criteria for diving fitness. Forty-two candidates for regular naval diving activity were included in the study. Tympanograms of both ears at 1 and 1.1 absolute atmospheres (ATA) were taken inside a pressure chamber with the subjects in two positions: seated and supine. At a pressure of 1 ATA, type A tympanograms were found in all 84 ears examined. At a pressure of 1.1 ATA, with subjects in the upright position, 19 (22.9%) of the ears had type C and 2 (2.4%) type B tympanograms, while with subjects recumbent during descent, 6 of the ears (7.2%) had type C and 7 (8.4%) type B. Our results suggest that successful autoinflation at surface ambient pressure does not necessarily reflect middle ear pressure equalization ability during descent in a dive.