The real-life benefit of hearing preservation cochlear implantation in the paediatric population

  • Simone Schaefer

Student thesis: Master of Philosophy


Abstract Background The technique of attempting to preserve residual acoustic low-frequency hearing has become established in the field of paediatric cochlear implantation (hearing preservation cochlear implantation, HPCI). When successful, this technique has the potential of combining electric stimulation (ES) of the high-frequencies via the CI, with acoustic stimulation of the low-frequencies. Based on our understanding of the auditory information perceived by the low-frequencies, adding this acoustic signal to ES could lead to improved outcomes in complex real-life listening situations. The aim of this thesis is to meaningfully evaluate the 'real-life' benefit of preserved low-frequency acoustic hearing in children with a CI, using outcome domains and measurement instruments that have direct applications to activities of daily life. Methods A systematic search was performed to identify the current evidence on benefits of HPCI. The PRISMA guidance for systematic reviews was followed throughout. Subsequently, a retrospective cohort study was performed of our paediatric HPCI recipients investigating the success rate of HPCI and comparing this to the literature. A protocol was devised for qualitative study, where participants complete a topic guide to identify key themes, relevant to our target population. Lastly, a study was set up exposing participants to tests in spatial release from masking, complex pitch ranking, melodic error detection, perception of prosodic features in speech and cochlear dead regions to explore the 'real-life' benefits of paediatric HPCI. Results The systematic review included 37 papers, that showed that HPCI was associated with better speech perception in noise and music perception, whilst revealing no significant benefit in speech perception in quiet and binaural cues. We went on to demonstrate complete hearing preservation in 71% of ears with functional hearing preserved in 96% of ears. Results for both the qualitative and quantitative study are outstanding whilst we are awaiting recruitment. Conclusion Preserving residual low-frequency hearing is reliably achievable following CI in the paediatric population. Furthermore, the current literature supports the hypothesis that HPCI comes with meaningful 'real-life' benefits for both adults and children, specifically for speech perception in noise and music perception. However, the evidence is limited, and results vary between studies.
Date of Award1 Aug 2022
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorIain Bruce (Supervisor), Martin O'Driscoll (Supervisor) & Karolina Kluk-De Kort (Supervisor)


  • sensorineural hearing loss
  • child
  • cochlear implantation
  • hearing preservation

Cite this