[Postmortem changes in ear canal resonance and tympanic membrane impedance in the human ear].
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 the vibration behaviour of the tympanic membrane, as well as the ear canal resonance, during the time between death and preparation of the temporal 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 temperature and time after death. In a female human body we defined the resonance of the outer ear and the impedance of the tympanic membrane using a tympanometer and a real ear measurement system during nine hours post mortem.


RESULTS
We were able to prove that before the preparation of the temporal bone none of the parameters changed significantly.


CONCLUSIONS
In conclusion, the method of preserving the bone after its preparation is decisive for the validity of measurements at the isolated (post mortem) human temporal bone.
Vitzthum
H G
HG
Otto-von-Guericke-Universität Magdeburg, Medizinische Fakultät, Universitäts-HNO-Klinik.
Vorwerk
U
U
Scheinpflug
L
L
Begall
K
K
D000158:Acoustic Impedance Tests; D000162:Acoustics; D000368:Aged; D001844:Bone Conduction / Q000502:physiology; D003187:Compliance; D004424:Ear Canal / Q000473:pathology*; D004429:Ear Ossicles / Q000473:pathology; D005260:Female; D006801:Humans; D011180:Postmortem Changes; D012016:Reference Values; D013997:Time Factors; D014432:Tympanic Membrane / Q000473:pathology*
Zur Untersuchung postmortaler Veränderungen von Gehörgangsresonanz und Trommelfellimpedanz am menschlichen Ohr.