High-Speed Video Observation of Tympanic Membrane Rupture in Guinea Pigs

In this study, the tympanic membrane (TM) of the guinea pig was exposed to a blast wave generated by micro-explosion of 10mg silver azide, and the time history of TM rupture was recorded using a high-speed video camera. The relationship between the process of TM rupture and the peak pressure of the blast wave was then examined. The critical value which caused the TM rupture was found to be 192dB SPL (79.6kPa), and when this level of pressure was applied to the TM, tears were immediately caused in the radial direction, although they did not subsequently expand. When pressures above 195dB SPL (112kPa) were applied to the TM, it suffered a perforation, and this perforation continued to expand for several milliseconds, even after disappearance of the pressure change caused by the blast wave.