'Real-life' benefit of hearing preservation cochlear implantation in the paediatric population: a single-site case–control study

INTRODUCTION: Cochlear implantation with hearing preservation (HPCI) has allowed a cochlear implant (CI) electrode to be implanted while trying to preserve residual acoustic low-frequency hearing. The concept arises from the importance of this low-frequency information and the limitations of a CI in several auditory domains. The combination of electrical hearing with either preserved acoustic hearing or amplified ‘natural’ hearing has the potential to address these issues and enable children with HPCI to closely follow normal auditory development. The aim of this study is to evaluate the ‘real-life’ benefit of preserved acoustic low-frequency hearing in children with a CI, understand the benefits of preserved natural hearing in complex listening situations and so enable parents and children to make an informed choice about implantation. Ultimately, helping to ensure the maximum number of children benefit from this life-changing intervention. METHODS AND ANALYSIS: Nineteen ears in children and young people aged 6–17 years old with ‘successful’ HPCI will be subjected to a test battery consisting of: (1) spatial release from masking; (2) complex pitch direction discrimination; (3) melodic identification; (4) perception of prosodic features in speech and (5) threshold equalising noise test. Subjects will be tested in the electro-acoustic stimulation (EAS)/electro-natural stimulation (ENS) and the electric-only (ES) condition, thereby acting as their own control group. Standard demographic and hearing health information will be collected. In the absence of comparable published data to power the study, sample size was determined on pragmatic grounds. Tests are exploratory and for hypothesis-generating purposes. Therefore, the standard criterion of p<0.05 will be used. ETHICS AND DISSEMINATION: This study has been approved by the Health Research Authority and NHS Research Ethics Committee (REC) within the UK (22/EM/0017). Industry funding was secured via a competitive researcher-led grant application process. Trial results will be subject to publication according to the definition of the outcome presented in this protocol.