Research indicates that children with single-sided deafness (SSD) have poorer linguistic and academic skills than their normal hearing peers (Lieu et al 2010, Arras et al 2021, Park et al 2022). Binaural hearing enables localization of sound and provides access to information needed to hear and understand speech in complex listening situations. Children with SSD lack binaural cues and may experience difficulties with speech perception in noise and sound localization compared to children with normal hearing (Griffin et al 2019, van Wieringen et al 2019). With a CI in the deaf ear, it has to some extent become possible to recreate binaural hearing in children with SSD.

The impact on the development of children with SSD with cochlear implant remains unclear since many aspects have not been researched in detail and no data from children with SSD and a CI in Denmark exist despite the relatively large group of children implanted. The project is innovative, as the children will be followed up in a longitudinal design and results will contribute to the knowledge about 1) the development of hearing in children with SSD and a CI, 2) the development of complex language skills of children with SSD and CI compared to children with bilateral CI and normal hearing children and 3) the need for a CI when a child is a teenager. The project will generate significant knowledge for the benefit of future treatment for patients with SSD and provide the children with SSD the fundament for the best social and academic display.

The purpose of the project is to clarify whether children with SSD will benefit from having a cochlear implant, including whether the benefit depends on the implantation age. The latter is very important, since several studies (Eg. Arras et al., 2021, 2022, 2023) only include children implanted below three years of age, while several children become unilaterally deaf at a later age.