Cochlear implantation: auditory perception in prelingually deaf children

Abstract

The aim of this study was to evaluate the influence of age at implantation on the auditory performance of prelingually deaf children following multichannel cochlear implantation. The authors evaluated 115 prelingually deaf children. The ages at implantation ranged from 21 to 84 months (average age, 51.8 months). The duration of deafness ranged from birth to 34 months (average, 6.3 months). The children’s developing use of audition was evaluated with Categories of Auditory Performance (CAP) 1, 2, 3, 4, and 5 years following implantation. The results revealed that 80% of children who reached 5 years after implantation could understand conversation without lip-reading whereas the same children (100%) did not have any awareness of environmental sounds before implantation. Twenty-three children who reached the 3-year follow-up were assigned to one of three age groups, according to age at implantation: group A (21 months–3.5 years, n = 10), group B (3.5–5 years, n = 14), and group C (5–7 years, n = 9). The Mann–Whitney U test was used to compare outcomes. The analysis revealed that CAP score was higher in group A in comparison with group B (P = 0.01) and group C (P = 0.001); whereas there was no significant difference between groups B and C. These results indicate that prelingually deaf children implanted before the age of 3.5 years will outperform (in CAP scale and in the 3–year interval after implantation) children implanted at older ages. Although this has a significant impact on current clinical practice (great need for earlier identification of deafness and earlier intervention), it should not exclude older children who also derived benefit from cochlear implantation and showed considerable progress in auditory perception.