Children with single-sided deafness (SSD) experience difficulties with localizing sounds and understanding speech in noisy environments and may also be at risk for speech-language delays. Over the past decade, 3 groups of children were followed up at regular intervals: children with SSD who had received a cochlear implant (CI) in the deaf ear at a very early age, children with SSD, and children with bilateral normal hearing. Longitudinal analyses show that the children with SSD who did not receive a CI were at risk for grammar skills, poorer speech perception in noise, sound localization, and verbal IQ. Children with SSD and CI were on par with normal hearing children regarding grammar and speech perception in noise. An overview of the main findings will be given. These confirm that children with prelingual SSD can benefit from a CI provided at an early age to support their development across multiple domains. The longitudinal data led to a federal policy change in health care in Belgium in 2024.

Acknowledgements: The studies were conducted by Anouk Sangen and Tine Arras between 2014 and 2024. The multi-center partners were Christian Desloovere, Jan Wouters (University Hospital Leuven, ExpORL, Dept Neurosciences, KU Leuven), An Boudewyns (University hospital Antwerp, University of Antwerpen), Ingeborg Dhooge (University hospital Gent, University Gent), Erwin Offeciers, Andrzej Zarowski (European Institute for ORL-HNS), and Birgit Philips (Cochlear Ltd Mechelen). The research was funded by the European Union [grant number FP7-60713], by VLAIO [grant number HBC.2020.2308], as well as the Research Foundation Flanders [grant number T002216N]. These grants were awarded to the KU Leuven. The cochlear implants and clinical support were funded by Cochlear Ltd throughout the study. All data have been published.