Measuring Listening Challenges in Children Using Cochlear Implants

Cochlear implants have supported remarkable gains for oral communication in children. Yet, it is important to remember that auditory prostheses including cochlear implants do not restore normal hearing and that oral development achieved with these devices is typically acquired with therapy/training and effort. In our laboratory, we have used a number of techniques to explore auditory development in cohorts of children with hearing loss who use one cochlear implant either alone (unilateral) or with a hearing aid (bimodal hearing) or bilateral cochlear implants. First, reaction time has been measured in addition to accuracy in tasks of music and speech perception. Reaction time has been important for revealing delays in response by children using unilateral devices compared to normal hearing peers and improvements in children using bilateral devices. Second, pupillometry has been used to quantify task difficulty. Pupil diameter was strongly and positively related to changes in reaction time in a group of bilateral cochlear implants users in bilateral listening tasks, revealing abnormal challenges in the cochlear implant group. Third, auditory evoked cortical potentials reveal changes in the left frontal and right parietal areas in cochlear implant users. These changes occurring beyond the auditory cortices in the temporal lobes suggest compensatory mechanisms to support hearing in children using cochlear implants. In sum, a combination of measures to track auditory development are being used to identify challenges for listening in children using cochlear implants.