The ECochG Study

  • Research type

    Research Study

  • Full title

    Utilising electrocochleography (ECochG) to investigate the physical interactions between cochlea fine structures and electrode array during insertion in Children and young people (CYP) with residual natural hearing- an exploratory study



  • Contact name

    Iain Alexander Bruce

  • Contact email

  • Sponsor organisation

    Manchester University NHS Foundation Trust

  • Duration of Study in the UK

    1 years, 0 months, 1 days

  • Research summary

    Results from cochlear implantation (CI) with attempted preservation of natural hearing (HPCI) remain variable, our understanding of factors influencing success is increasing, including surgical technique, steroid usage, ‘patient factors’ and physical characteristics of the electrode array. The use of a “soft” surgical technique – comprising steroid use, atraumatic technique at the insertion site and slow electrode advancement – has led to high rates of successful hearing preservation. We demonstrated (in publication) that consistently good hearing preservation results are possible using the CochlearTM Nucleus® Profile with Slim Straight Electrode in children. Despite the success of hearing preservation surgery, there is considerable variability in benefit across listeners, and rates of preservation are highly variable across patients. It is difficult to know whether residual hearing was preserved during surgery until postoperative evaluation is completed. Furthermore, from the experience with HPCI in children, it has appeared challenging to maintain preserved hearing over a prolonged period. In some cases, there has been documented an improvement in natural hearing thresholds post CI surgery but the mechanisms for this are unknown.
    Electrocochleography (ECochG) is an electrophysiological technique that records electrical potentials generated by the inner ear and cochlear nerve when acoustical stimulated. It is composite response of the cochlear microphonic (CM), summating potential (SP), compound action potential (CAP) and the auditory nerve neurophonic (ANN). Within the last decade, there has been interest in the utility of ECochG use during cochlear implantation. It allow the monitoring of cochlear trauma during electrode insertion and dynamic physical interactions during electrode insertion. There is a lack of data supporting objective outcomes of HPCI and ECochG. In this study, by exploring the relationship between ECochG intraoperatively and HPCI outcome measures, it will support us to predict hearing outcomes, inform surgical technique, understand postoperative physiology, and provide further understanding of the mechanisms of hearing preservation.

  • REC name

    East of England - Cambridgeshire and Hertfordshire Research Ethics Committee

  • REC reference


  • Date of REC Opinion

    20 Dec 2023

  • REC opinion

    Favourable Opinion