Cochlear implants in young children: the relationship between speech perception and speech intelligibility.

Abstract

To determine the relationship between measures of speech perception and speech production after cochlear implantation of young children with profound congenital and prelingual deafness. A prospective study was undertaken on a consecutive group of children with profound deafness. There were 126 children at the preimplantation interval and 71, 50, 26, and 20 children, respectively, at the 2, 3, 4, and 5 yr follow-up after implantation. Speech perception and speech intelligibility were assessed using hierarchical rating scales. Spearman rank correlation coefficients were used to determine the statistical correlations. All patients were either congenitally deaf or deafened before the age of 3 yr and were implanted before age 7 yr. The patients all received the Nucleus multichannel cochlear implant system with the most appropriate speech encoding strategy. Speech intelligibility at 5 yr was strongly correlated with speech perception at the 2, 3, 4, and 5 yr intervals after implantation (Spearman coefficients 0.77, 0.81, 0.58, 0.58; p < or = 0.01). Speech intelligibility at the 2, 3, and 4 yr intervals also correlated in a similar manner with earlier speech perception abilities (p < or = 0.01). The results suggest that speech intelligibility between 2 and 5 yr after implantation in young children with congenital and prelingual profound deafness can be predicted by measures of earlier speech perception.