Effects of middle ear pressure changes on umbo vibration.
Effects of middle ear pressure changes on umbo vibration were studied in 5 fresh human temporal bones taken from cadavers. Umbo vibration to a constant sound pressure of 120 dB SPL at the tympanic membrane was measured with an MTI 1000 Fotonic Sensor. The results showed that there was a loss of umbo vibration at lower frequencies below 2 kHz; 5.0 +/- 1.0 dB loss at -100 mmH2O, 9.2 +/- 1.3 dB loss at -200 mmH2O, and 13.1 +/- 1.8 dB loss at -300 mmH2O. In contrast, there was a slight increase in umbo vibration at around 2-3 kHz. The effect was considered to be mainly due to increased stiffness of the tympanic membrane and decreased air volume in the middle ear cavity.
Gyo
K
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Department of Otolaryngology, Ehime University, Japan.
Goode
R L
RL
D002102:Cadaver; D004432:Ear, Middle / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D011312:Pressure; D013701:Temporal Bone / Q000502:physiology; D014432:Tympanic Membrane / Q000502:physiology*; D014732:Vibration