(A) A sturdy acrylic frame supports a force sensor and piezolectric motor. The piezoelectric motor advances in the direction of the arrow to contact the specimen, which rests on a stage attached to the force sensor. (B) An enlarged view of the indenter, which is tipped with a 300 μm diameter ruby sphere. The positionable mounting platform allows the specimen to be oriented such that the scala tympani is positioned just below the probe, with the BM, OSL, and RM approximately perpendicular to the insertion axis.