Onwards and inwards: The direction of travel for intraoperative monitoring during cochlear implant electrode insertion.

Cochlear implants (CIs) are the most successful neural prosthesis ever developed. While cochlear implantation was initially indicated for those with profound hearing loss, the evolving candidacy criteria has expanded to include those with low-frequency residual natural hearing. The development of ''soft'' surgical techniques has led to the ability to preserve residual hearing. This hearing preservation is particularly important for ''real-life'' listening. However, there remains a large amount of variability in rates of hearing preservation and CI outcomes. Understanding the factors that influence this variation is key. There is evidence that the overall health of the cochlea and its interaction with the CI, could potentially play a key role. Cochlear implant manufacturers have recognised this challenge, and tools to measure and monitor the health and this interaction are evolving. This editorial seeks to outline and position traditional electrophysiological testing and novel measurement tools and speculate on future utilisation in cochlear implantation.