Insertion of electrode array in scala vestibuli, rather than the preferred location within scala tympani, leads to loss of native hearing in those patients with isolated high-frequency hearing loss undergoing cochlear implantation.

We aim to determine the surgical placement in patients with high frequency who had long electrode array insertions because they did not meet audiometric criteria for short array devices.

From this basis we will be able to determine if suboptimal insertion (e.g., in the scala vestibuli) leads to loss of low-frequency hearing in these patients. We also will look at the possibilities of using this data in predicting outcomes, modifying implant design, and perfecting surgical technique.

Inclusion Criteria:

• Registered in the Cochlear Implant Database.
• Patient has short or long electrode cochlear implant for high frequency hearing loss.

Exclusion Criteria:

• Inability to provide consent.
• Patients with underlying otospongiosis, extensive labyrinthitis ossificans or cochlear dysplasia. (These patients would have been identified with pre-operative imaging prior to cochlear implantation).

Either part of the existing Cochlear Implant data base, or those persons who have had a Cochlear implant with either short or long electrode array who have had a high frequency hear loss.