From the FDA:
Advanced Bionics (AB), a global leader in developing advanced cochlear implant systems, announced today that it has notified the US Food & Drug Administration (FDA) that it will voluntarily recall its HiRes 90K cochlear implant device and is retrieving all unimplanted devices in distribution. This action is being taken in response to two confirmed instances where the product experienced a malfunction requiring explantation. These recipients experienced severe pain, overly loud sounds and/or shocking sensations at 8-10 days after initial activation of their device.
AB is continuing to evaluate the root cause(s) of the problem and is working closely with the FDA to address their questions and concerns, and institute changes to the product to ensure that the HiRes 90K has the highest quality for patients who use the device. This voluntary action is being taken to ensure continued patient safety and product quality. The risk of any significant adverse medical events appears to be remote at present.
http://www.fda.gov/Safety/Recalls/ucm234901.htm