Participants:
  • 188 children with cochlear implants (CIs) from 6 implant centers throughout the US
  • 97 children with normal hearing (NH) from 2 university-affiliated preschools (first 8 years of the study only)

​Main enrollment criteria:
  • age 5 years or younger at baseline (pre-implantation for CI recipients)
  • pre- or post-lingually deaf and a candidate for a cochlear implant (unilateral or bilateral)
  • family must commit to educating child in English-speaking schools
  • at least some English must be spoken in the household

Enrollment:
  • November 2002 to December 2004

​Follow-up:
  • visits every 6 months for the first 3 years post-implantation, with annual visits thereafter