The objective of this study was to produce an improved finite element (FE) model of the human middle ear and to compare the model with human data. We began with a systematic and accurate geometric modeling technique for reconstructing the middle ear from serial sections of a freshly frozen temporal bone. A geometric model of a human middle ear was constructed in a computer-aided design (CAD) environment with particular attention to geometry and microanatomy. Using the geometric model, a working FE model of the human middle ear was created using previously published material properties of middle ear components. This working FE model was finalized by a cross-calibration technique, comparing its predicted stapes footplate displacements with laser Doppler interferometry measurements from fresh temporal bones. The final FE model was shown to be reasonable in predicting the ossicular mechanics of the human middle ear.

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Accurate FE modeling, incorporating both morphometric and interferometric performance data, predicted both normal and pathologic mechanical performance of the human ossicular chain.

Soft tissue silicone-casting techniques, spot-film radiography and cineradiography were combined to examine the in situ anatomy and movement of the upper airway structures in live-phonating and dead delphinid porpoises. Three species, Tursiops truncatus, Tursiops gilli, and Stenella longirostris were studied under high-speed x-ray motion picture cameras to observe the movements in the laryngeal and nasal regions associated with sound production. Accurate reconstructions of the nasal sac anatomy were made by associating castings of silicone rubber, with various x-ray photographs using radiocontrast materials. Sounds produced during the video recordings were simultaneously recorded through a contact piezoelectric hydrophone and stored on magnetic tape. Movement of the left nasal plug was found to be precisely associated with internal whistle production, and the right nasal plug was speculated to be the source of internal click production. Externally produced sounds were generated at the blowhole and the air supply control mechanism was found to be the same for all three types of phonation. The nasopharyngeal air space in the anteroventral portions of the skull and in the bony nares controlled the outward movement of air into the upper passages. The nasopharyngeal muscular "pump" also functioned in withdrawing spent air back down from the upper passages.