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

Streamline fitting of speech processors using automatically recorded ECAPs

Meeting Abstract

  • corresponding author A. Morsnowski - HNO-Klinik, Christian-Albrechts-Universität, Kiel
  • J. Müller-Deile - HNO-Klinik, Christian-Albrechts-Universität, Kiel
  • M. Hey - St. Salvator Krankenhaus HNO-Klinik, Halberstadt
  • K. Begall - St. Salvator Krankenhaus HNO-Klinik, Halberstadt
  • T. Wesarg - HNO-Klinik, Universitätsklinikum Freiburg
  • R. Laszig - HNO-Klinik, Universitätsklinikum Freiburg
  • M. Killian - Cochlear AG, Basel
  • A. Zarowski - Department of Otorhinolaryngology, M.I.St. Augustinus Hospital, Wilrijk-Antwerp
  • E. Offeciers - Department of Otorhinolaryngology, M.I.St. Augustinus Hospital, Wilrijk-Antwerp
  • P. Ambrosch - HNO-Klinik, Christian-Albrechts-Universität, Kiel

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. Doc05omci018

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

Published: May 31, 2005

© 2005 Morsnowski 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.




Different fitting methods to create speech processor maps are investigated as part of a multi-centric study to evaluate the Nucleus system 4.

Materials and Methods

In clinical practice, adult CI recipients are fitted with maps at stimulation levels based on psycho-acoustical measurements. For toddlers, stimulation thresholds (T-) and comfortable stimulation levels (C-levels) have to be estimated by the use of objective methods like Neural Response Telemetry (NRT) and electrically evoked stapedial reflex threshold measurements.


System 4 assists the partly automated creation of maps. It is possible to record the ECAP thresholds automatically with NRT (T-NRT). Only these T-NRT and a pair of T/C-level of a single electrode are needed to generate a map, a so called streamline map. The intra- and post-operative T-NRTs of 25 post-lingually deafened adults with less than 15 years of deafness are estimated automatically as well as manually for five electrodes and compared to each other. The T-NRT based streamline maps are compared with psycho-acoustically fitted maps for a subset of the recipients in terms of the Freiburg monosyllable speech-intelligibility tests.


Although the T/C-levels of some electrodes differ significantly between the streamline and the behavioural maps, the test scores are mainly indistinguishable intra-individually. The recipient's preference for one of these maps depends on the recipient and may change with time.