Vestibular effects of barotrauma were studied by morphological methods using SEM in guinea pigs. The animals were placed in a high pressure chamber and the pressure increased from 1 ATA to 2 ATA in 10 minutes, maintained at 2 ATA for 10 minutes before reducing the pressure to 1 ATA in 1 minute. Stereomicroscopy showed round window membrane rupture in most of the animals; the outstanding SEM change was a slight hair cell damage in the crista ampullaris area. Disruption and disappearance of hairs of sensory cells in the crista were observed immediately following the sudden reduction of pressure. After 2 weeks, a few supporting cells replaced the damaged hair cells in the crista.
