Consequences of auditory experience and cochlear implant stimulation on tuning and other measures obtained in pre-lingually deaf children and postlingually deaf adults

Children and adults with moderate to severe hearing loss may obtain cochlear implants (CIs) to restore auditory perception, but auditory development differs among them. We have compared various peripheral measures across CI listeners differing in etiology, age of onset and duration of hearing loss, and duration of CI use. Several measures assess the efficacy with which CI electrodes activate their target auditory neurons in individuals with varying hearing demographics. In addition to peripheral contributions to auditory perception, central reorganization might occur when the auditory nerve is stimulated with coarse, electrical input from CIs. Evidence from neurophysiological studies in cats suggest that the central representation of spectral/spatial resolution is altered by chronic CI stimulation. In humans, psychophysical tuning curves might reflect both the spread of electrical current in the cochlea and the central representation of electrical stimuli. Understanding how chronic, electrical stimulation during auditory system development affects spectral resolution may be useful for optimizing CI programming in children and adults.