| Abstrakt: |
C57BL/6 inbred mice were subjected to simulated sonic booms of different rise time, intensity, and number of sonic booms. The most important pathological change was found to be bleeding in the basal turn of the scala tympani of the inner ear. Even a single boom having a rise time of 0.1 msec, peak overpressure of 3.3 psf, and duration of 120 msec was found to cause bleeding in at least one inner ear of each exposed mouse. Similar results occurred for a single ''superboom'' having a 10-psf peak overpressure but a longer rise time of 5 msec. The frequency of the appearance of blood clots in the scala tympani was found to increase with the number of booms administered. This cumulative effect was observed even when the booms were administered at the rate of one every 24 h. The traces of bleeding usually disappeared within a period of eight weeks. The extent of the bleeding in the scala tympani did not increase when mice were exposed to a rapid succession of simulated sonic booms (18 000 booms in one hour). However, three out of twenty mice suffered a rupture of the basilar membrane and destruction of the Corti organ in the basal turn of the cochlea. Subject Classification: [43]65.20, [43]65.40; [43]50.70; [43]80.40. [ABSTRACT FROM AUTHOR] |
