Audio Signal Processing for Cochlear Implants

TNT members involved in this project:
Prof. Dr.-Ing. Jörn Ostermann

Cochlear implants are widely accepted as the most effective means of improving the auditory receptive abilities of people with profound hearing loss. Some cochlear implant recipients can now communicate without lip-reading or signing, and some can communicate over the telephone. Generally, these devices consist of a microphone, a speech processor, a transmitter, a receiver, and an electrode array which is positioned inside the cochlea. The speech processor is responsible for decomposing the input audio signal into different frequency bands or channels and delivering the most appropriate stimulation pattern to the electrodes. Electrodes near to the base of the cochlea transmit high-frequency information, whereas those near to the apex transmit low-frequency information.

The main goals of the project are to improve speech intelligibility in noise situations and to improve music perception with cochlear implants.

Although understanding in quiet situations is no longer a major problem for most cochlear implants recipients, hearing in noisy conditions is still severely limitied. Nevertheless, thechnical progress in signal processing for cochlear implants in recent past led to remarkable performance enhancements in device users. Therefore, we design new signal processing strategies for cochear implants. The new algorithms are tested with cochlear implant patients in the Hoerzentrum of the Medical University of Hannover.

[1] W. Nogueira, A. Buechner, Th. Lenarz, B. Edler,
"A Psychoacoustic NofM type speech coding strategy for cochlear implants", Eurasip Journal on Applied Signal Processing special issue on DSP in Hearing Aids and Cochlear Implants, Vol. 18, 3044-3059, November, 2005.
[2] W. Nogueira, A. Giese, B. Edler, A. Buechner,
"Wavelet Packet Filterbank for Speech Processing Strategies in Cochlear Implants", 2006 IEEE International Conference on Acoustics, Speech, and Signal Processing 14-19 Mai 2006, Toulouse, France.
[3] W. Nogueira, B. Edler, C. Frohne-Büchner, M. Brendel, A. Buechner,
"Sinusoidal Analysis of Audio for Current Steering Strategies in Cochlear Implants", CI-2006 - 9th International Conference on Cochlear Implants, June, 2006, Vienna, Austria.
[4] W. Nogueira, A. Buechner, B. Edler,
"Fundamental Frequency Coding in NofM Strategies for Cochlear Implants", Preprint 6515, 118th AES Convention, Barcelona, Spain, 2005.

Show all publications
  • Reemt Hinrichs, Tom Gajecki, Jörn Ostermann, Waldo Nogueira
    A subjective and objective evaluation of a codec for the electrical stimulation patterns of cochlear implants
    Journal of the Acoustic Society of America, March 2021
  • Jörn Ostermann, Reemt Hinrichs
    Links und rechts verbinden
    Unimagazin, Leibniz Universität Hannover, No. 1, June 2020
  • Jörn Ostermann Reemt Hinrichs
    Signal Coding for Binaural Signal Processing in Cochlear Implants
    Binaire, October 2019