Download Children with congenital unilateral sensorineural hearing loss: The

 Children with congenital unilateral sensorineural hearing loss: The effect of auditory stimulation in the impaired ear during development. Marlin Johansson, Division of Ear, Nose and Throat Diseases [email protected] AIM: The overall purpose of this Ph.D. project is to study the causes and mechanisms behind various degrees of congenital unilateral sensorineural hearing loss (cUSNHL) and the effect of early intervention on these children's perceptual skills and maturation of the auditory pathways. BACKGROUND: Unilateral hearing loss (UHL) is an asymmetric condition with normal hearing in one ear and some degree of hearing impairment in the other ear. The reduced or complete absence of auditory stimulation from one ear to the brain can cause neural reorganization and effortful listening. Several studies have shown that children with untreated UHL have greater social‐emotional and academic difficulties compared to normal hearing children. It is beneficial to receive similar auditory input from both ears to effectively focus and understand speech in environments with competing speech sources, and when localizing sounds. At Karolinska University Hospital, we have a unique opportunity to systematically analyze and follow UHL that are present at birth, due to a highly efficient universal newborn hearing‐screening programme. The focus of the Ph.D. project is on nonsyndromic cUSNHL. It is a lifelong and hard to master hearing impairment that may, if not treated early, generate irreversible detrimental neural reorganization and impaired binaural hearing. The incidence of cUSNHL is 0.05‐0.06%, corresponding to more than 1000 children in Sweden. METHODS: The research plan is divided into 3 studies (4 papers) that will run over 5 years. Study I: The causes and mechanisms behind cUSNHL along with functional characterization of the hearing impairment will be studied. Study Il: The effect of hearing aid amplification on sound localization accuracy and speech‐in‐speech recognition, using subjective and objective tests will be quantified. The effect of early vs late hearing aid intervention on binaural hearing will be studied (2 papers). Study 111 : The effect of cochlear implantation on unilaterally‐driven reorganization at the level of the auditory nerve, brainstem and the auditory cortex will be studied. CONTRIBUTION : The Ph.D. project will provide one of the first projects studying causes, mechanisms and very early treatment options of cUSNHL in pediatric patients. The results from the Ph.D. project will be a foundation for clinical guidance of how to test children with cUSNHL, as well as when and how to provide the best possible technical intervention to restore binaural hearing.