Assessment of vibration characteristics of different cartilage reconstruction techniques for the tympanic membrane using scanning laser vibrometry

The sound transmission properties and resulting hearing improvement of reconstruction of the tympanic membrane are strongly influenced by the material and geometry of the transplants used. Combining mechanical stability and biocompatibility cartilage is a widely-used reconstruction material in tympanoplasties. However, different: reconstruction techniques use differ ent shapes and positions of cartilage slices, e.g., cartilage plate, palisade technique, and island technique. The aim of the present study was to investigate the sound transmission properties of different reconstruction techniques. Therefore, vibrational amplitudes of the various transplants were measured by means of scanning laser vibrometry using an ear canal-tympanic membrane model. When exposed to a defined acoustic sound excitation, different frequency response functions were found for different reconstruction techniques. The results demonstrated that, apart from material characteristics, the sound transmission properties of the reconstructed tympanic membrane were strongly influenced by the reconstruction technique.