Effect of middle ear components on eardrum quasi-static deformation

• Published in: Hearing research Vol. 157; no. 1; pp. 124 - 137
• Main Authors: Dirckx, J.J.J., Decraemer, W.F.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.2001; Elsevier
• Subjects: Animals; Auditory Threshold - physiology; Biological and medical sciences; Biophysical Phenomena; Biophysics; Dissection; Ear and associated structures. Auditory pathways and centers. Hearing. Vocal organ. Phonation. Sound production. Echolocation; Ear, Middle - anatomy & histology; Ear, Middle - physiology; Female; Fundamental and applied biological sciences. Psychology; Gerbillinae; In Vitro Techniques; Middle ear; Movement - physiology; Ossicle; Pressure; Temporal Bone - anatomy & histology; Temporal Bone - physiology; Tympanic membrane; Tympanic Membrane - anatomy & histology; Tympanic Membrane - physiology; Vertebrates: nervous system and sense organs; Tympanic membrane; Middle ear; Pressure; Ossicle; Tympanum; Deformation; Temporal bone; Rodentia; Mechanical properties; Inner ear; Displacement; Organ of hearing; Vertebrata; Mammalia; Ear ossicles; Cochlea; Gerbil
• ISSN: 0378-5955; 1878-5891
• DOI: 10.1016/S0378-5955(01)00290-8

Eardrum deformation induced by quasi-static middle ear pressure was studied at progressive stages of dissection of gerbil temporal bones. With our high resolution moiré interferometer we recorded the shape and deformation of the eardrum along a line perpendicular to the manubrium and through the umbo, at different middle ear pressures. The deformation was measured from the medial side, after serially removing the cochlea, removing the stapes, cutting the tensor tympani, exposing the incudo-mallear joint, and cutting the anterior bony process which connects the malleus to the tympanic bone. The mean displacement as a function of pressure was also determined at all stages of dissection. Removing the cochlea and stapes, and cutting tensor tympani has no effect on static eardrum deformation. Exposing the incudo-mallear joint increases eardrum movement, and cutting the anterior bony connection between malleus and temporal bone strongly changes eardrum rest position and further increases its displacement.