Figure 1. Experimental approach and control.

A: Schematic of the experimental design for characterization of the ME system using a laser Doppler vibrometer, micro-pressure sensor and Sokolich probe-tube microphone. Velocity responses were measured along the ossicular chain, especially at the stapes while simultaneous pressure measurements were made at the tympanic membrane close to the umbo (P_TM) and in scala vestibule next to the stapes (P_Stapes). B: Effects of the SV hole on stapes LTF. Black and gray solid lines stand for average stapes LTFs across 11 TBs under the condition of cochlea intact and after the SV hole was made. Corresponding thin-dotted lines represent ±1 standard diaviation. In addition, averaged velocity responses from sourrounding bone normalized to P_TM together with ±1 standard diaviation were plotted as the gray dashed curve. C and D: effects of leaving SV hole unsealed on MEPG. C: Example from preparation of TB #30 demostrates MEPG under the condition of SV not sealed (solid gray line) or the SV fenestration sealed with Jeltrade (solid black line), respectively. D: MEPG variation upon slealing versus leaving the SV hole open. Thick line stands for average results across three individual TBs (thin lines). The maximum average variation of MEPG upon sealing the SV hole was ~2 dB. LTF: local transfer function; MEPG: middle ear pressure gain; P_Stapes: pressure in the SV next to the stapes; P_TM: pressure at the TM close to the umbo; SV: scala vestibule; TM: tympanic membrane.