Performance over time of congenitally deaf and postlingually deafened children using a multichannel cochlear implant

The speech perception performance of 10 congenitally deaf and 3 postlingually deafened children who received the Cochlear Corporation multichannel cochlear implant was examined and compared. The children were tested preimplant and at 6-month intervals up to 2 years using the Monosyllable-Trochee-Spondee test (MTS), the Word Intelligibility by Picture Identification test (WIPI), and Phonetically Balanced Kindergarten (PB-K) or Northwestern University List 6 (NU-6) word lists. The postlingually deafened children exhibited significantly improved performance on open- and closed-set tests of word recognition after 6 months of implant use, a pattern similar to that of postlingually deafened adult implant users. In contrast, the congenitally deaf children did not exhibit measurably improved performance on speech perception tests until after 12 months or more of implant use. With as much as 18-24 months of use, however, some congenitally deaf children demonstrated limited open-set word recognition.