AN INVESTIGATION OF CHANGES OF THE EAR CA NAL RESONANCE AND IMPEDANCEOF TYMPANIC MEMBRANE AT THE HUMAN EAR AFTER DEATH

Background: The human temporal bone preparation is a common model for research of physical processes of the ear canal and middle ear. in the past decade only a few reports were published discussing changes of t he vibration behaviour of the tympanic membrane, as well as the ear ca nal resonance, during the time between death and preparation of the te mporal bone. The aim of our study is to verify whether measurements at the temporal bone of dead humans can be really applied to the in vivo situation. Methods: We investigated whether changes of the ear canal resonance and the vibration of the tympanic membrane depend on tempera ture and time after death. In a female human body we defined the reson ance of the outer ear and the impedance of the tympanic membrane using a tympanometer and a real ear measurement system during nine hours po st mortem. Results: We were able to prove that before the preparation of the temporal bone none of the parameters changed significantly. Con clusions: In conclusion, the method of preserving the bone after its p reparation is decisive for the validity of measurements at the isolate d (post mortem) human temporal bone.