Most knowledge of the motion of cochlear structures has been limited to measurements through the round window at the extreme base of the cochlea or through a hole made in the cochlear capsule, which can modify cochlear mechanics. Optical coherence tomography (OCT) provides the ability to measure shape or motion of structures through a thin layer of tissue or bone. The motion of cochlear structures has been measured in the mouse cochlear apex without making an opening into the cochlea, using a custom OCT system. Here we describe intracochlear vibrometry using a commercial OCT system. Specimens were prepared by opening the middle ear while maintaining part of the cartilaginous ear canal. A Thorlabs 905nm Ganymede III-HR OCT system with 100-kHz camera frame rate was used to measure cochlear anatomy in a 2-D radial slice (B-scan) and dynamic displacements along a line (A-line) that intersected several cochlear structures in response to tones presented to the ear canal. Differences in the magnitude and phase of the displacements along the A-line show differences in the motion of cochlear structures. These data will provide information for validating 3D finite element models of the cochlea. [Work supported by NIDCD R01 DC07910.]