Single Sided Deafness - consequences for children's language development & intervention via early cochlear implantation.

Children with SSD, a congenital severe to profound sensorineural unilateral hearing loss ≥ 80 dB HL, constitute a patient group for which there is no standard care. It is widely acknowledged, however, that these children experience direct and indirect consequences of the one-sided sensory deprivation. The general aim of the present doctoral research was twofold. First, we aimed to contribute to the knowledge about the difficulties children with unaided SSD experience with regard to language skills and hearing abilities in daily life. We specially focused on a detailed insight of the language difficulties experienced, which was not present in the literature. The second aim was to set up a longitudinal study focused on the effectiveness of cochlear implantation as a possible remediation for very young children with SSD. Cochlear implantation is the only rehabilitative option that offers the potential to partially restore binaural hearing when implanted early in life, as it captures sound on the impaired side and transmits it to the brain via electrical stimulation of the auditory nerve. Research is required to determine the evidence for this in order to provide appropriate rehabilitation.

Our research showed that the language and hearing difficulties in school-aged children with unaided SSD are significant and should not be overlooked but rather warrant intervention. In our longitudinal study, we developed a protocol to follow the development of children with SSD implanted at a very young age. We focused not only on spatial hearing skills but also on linguistic and cognitive development. An important strength of the study is its between-subject design in which performance of the children with a cochlear implant is compared to those of children with SSD but no cochlear implant and to bilaterally normal hearing peers. Data of the first implanted children as of yet are very encouraging, but long term observation is of key importance in order to draw conclusions with regard to cochlear implant benefit. The present thesis provides the first step towards our goal of forming a well-founded advice to the Belgian National Health Insurance concerning reimbursement of a cochlear implant for young children with SSD.