Toward Accelerated and More Accurate Objective Fitting: Integrating Multi-Latency Measures of Auditory Processing in Cochlear Implant Patients

Background Cochlear implants provide a sensation of hearing to those who have severe to profound hearing loss by directly stimulating their hearing nerve. Each person with a cochlear implant has a unique story and hearing status, meaning audiologists often have to make significant adjustments to their implant settings. Finding the best settings for a person is challenging, as there is no efficient way to measure how well they can hear using different settings. Typically, the only way to understand if the settings are helping is to ask the person to describe the sensations being provided by their implant. This can be even more challenging when the person cannot communicate effectively with the audiologist, such as babies and young children. Therefore, many people using a cochlear implant may not be getting the best possible hearing outcomes. This may explain why people using cochlear implants vary widely in terms of their satisfaction with the implant and their ability to perceive speech, music, and/or environmental sounds. Aims To make sure that everyone who has a cochlear implant can fully benefit from it, we need to find new ways to tailor device settings to a person’s specific needs quickly and objectively. Researchers have developed ways to measure brain activity when someone hears sound through their implant, which could provide a better alternative to asking the person to describe what they’re hearing. However, these measurements take a long time and can be unreliable, which limits their usefulness in the clinic. Previous research in this area focused on making individual measurements to capture responses from a specific region of the brain. In this project, the researchers will instead (and for the first time) record responses from three parts of the brain simultaneously - the hearing nerve, the brainstem, and the cortex (all of which play a role in hearing) – in adults with cochlear implants. They will ask participants to judge the loudness of the sound they hear while recording their brain responses with both internal and external sensors, the internal ones being embedded in the implant, and the external ones placed on the scalp, and compare the results they obtain to understand how well they match. Benefit By studying how responses to sound in different parts of the hearing brain relate to the loudness perceived by a person using a cochlear implant, the researchers hope to develop a tool that audiologists can use to programme cochlear implants to match the user’s individual needs. This will help more people obtain the best hearing outcomes from their implant and more easily engage with the auditory world around them.