Figure 3.

Array crossing basilar membrane at 180°. The array originates in the scala tympani (ST) but crosses the basilar membrane into the scala vestibuli (SV) at approximately 180° (asterisk in A and B). The accuracy of the reconstruction is again verified by microdissection; in C, the point of transition between scalae is indicated by the thick arrow, with the thin arrow showing the tip of the array situated above the basilar membrane. “OS” indicates the osseous lamina of the basal turn, and “B” indicates the surface of the basilar membrane near the tip of the array. B and C give an inferiorly rotated view of the electrode path; in D, the specimen is tilted to show the array lying in the SV, above the basilar membrane; the straight line indicates the cut edge of the basilar membrane apical to the area occupied by the array(below the line is the ST of the lower apical turn). The arrow indicates the cut edge of the bony septum separating the SV of the middleturn from the ST of the apical turn. “S” indicates the stria vascularis immediately above the attachment zone of the basilar membrane; “M”labels the modiolus.