Performance of Toddlers, Children and Young Adults Using Unilateral or Bilateral Cochlear Implants on a Left versus Right Loudspeaker Identification Task

Thirty-six participants with bilateral cochlear implants aged 1-19 years completed a left versus right loudspeaker identification task. The majority performed at chance in the unilateral condition (n = 24) and significantly above chance in the bilateral condition (n = 28). Cluster analysis identified three groups; one group performed above chance in both conditions and was older at second implant and older at testing, with longer delay between implants. There were no such differences between the group performing at chance in both conditions and the group which scored highly in the bilateral condition only, thus demonstrating a bilateral benefit. Unilateral, but not bilateral, scores were correlated with age at second and at first implant, time between implants, and age at testing. Bilateral benefit was negatively correlated with age at second implant, time between implants and age at testing. Co-linearity made it difficult to isolate the relationships with demographic factors, though age at testing may have had the most influence on unilateral scores. Spatial hearing skills with bilateral implants cannot be predicted for individuals. Copyright (C) 2011 S. Karger AG, Basel