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Open Access

Signal Processing Strategies for Cochlear Implants Using Current Steering

  • Waldo Nogueira1Email author,
  • Leonid Litvak1,
  • Bernd Edler1,
  • Jörn Ostermann1 and
  • Andreas Büchner1
EURASIP Journal on Advances in Signal Processing20092009:531213

Received: 29 November 2008

Accepted: 22 September 2009

Published: 12 November 2009


In contemporary cochlear implant systems, the audio signal is decomposed into different frequency bands, each assigned to one electrode. Thus, pitch perception is limited by the number of physical electrodes implanted into the cochlea and by the wide bandwidth assigned to each electrode. The Harmony HiResolution bionic ear (Advanced Bionics LLC, Valencia, CA, USA) has the capability of creating virtual spectral channels through simultaneous delivery of current to pairs of adjacent electrodes. By steering the locus of stimulation to sites between the electrodes, additional pitch percepts can be generated. Two new sound processing strategies based on current steering have been designed, SpecRes and SineEx. In a chronic trial, speech intelligibility, pitch perception, and subjective appreciation of sound were compared between the two current steering strategies and standard HiRes strategy in 9 adult Harmony users. There was considerable variability in benefit, and the mean results show similar performance with all three strategies.


Processing StrategyCochlear ImplantAudio SignalWide BandwidthPublisher Note

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Authors’ Affiliations

Laboratorium für Informationstechnologie, Leibniz Universität Hannover, Hannove, Germany


© Waldo Nogueira et al. 2009

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.