gms | German Medical Science

Fourth International Symposium and Workshops: Objective Measures in Cochlear Implants

Medical University of Hannover

01.06. bis 04.06.2005, Hannover

Electrically evoked early potentials in the evaluation of CI-rehab

Meeting Abstract

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  • corresponding author D. Basta - Dept. of ENT at ukb, Berlin, Germany
  • A. Dahme - Hearing-Therapy-Center, Potsdam, Germany
  • I. Todt - Dept. of ENT at ukb, Berlin, Germany
  • A. Ernst - Dept. of ENT at ukb, Berlin, Germany

Medical University of Hannover, Department of Otolaryngology. Fourth International Symposium and Workshops: Objective Measures in Cochlear Implants. Hannover, 01.-04.06.2005. Düsseldorf, Köln: German Medical Science; 2005. Doc05omci039

The electronic version of this article is the complete one and can be found online at:

Published: May 31, 2005

© 2005 Basta et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.




The eCAP- and eABR-thresholds contain helpful information to improve speech processor fitting in very young or non-compliant patients. However, a clear correlation of these data and psychoacoustic measurements has not yet been possible due to high interindividual variability. It was therefore the aim of this paper to investigate the application of those data in the evaluation of hearing and speech rehab after cochlear implantation.

Materials and Methods

ECap`s of all electrodes were measured intraoperatively. After 6 weeks, three months and 1 year psychoacoustic T and MC-levels were determined in those patients capable of responding exactly and repeatably to stimulus changes. Speech perception and pure tone thresholds were tested three months and one year postoperatively and the results correlated with eCAP- and eABR-thresholds.


Patients which developed quickly a good speech perception ("good performers") showed a significantly higher correlation between eCAP-thresholds and the first (6 weeks postop.) psychoacoustic measurements than bad performers. The good performers also have lower pure tone thresholds after 3 months. One year postoperatively, the correlation between eABR-thresholds and psychoacoustic measurements was not more different between good- and bad performers. Interestingly, the pure tone thresholds are also not different between these patient groups.


The results suggest that patients which were able to perceive earlier and more precisely the electrical stimulus via cochlear nerve, the central auditory pathway could reach a higher level of speech understanding in a shorter period of time. The training of higher (e.g. cortical) speech processing mechanisms seems to be of most importance for optimizing of speech understanding than pure-tone hearing as estimated by eABR, eCAP and pure tone audiometry.