gms | German Medical Science

76. Jahresversammlung der Deutschen Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie e. V.

Deutsche Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie e. V.

04.05. - 08.05.2005, Erfurt

Interactions of combined electric/acoustic stimulation (EAS) of the cochlea in the central auditory system

Meeting Abstract

Suche in Medline nach

  • corresponding author Maike Vollmer - Department of Otolaryngology, Head and Neck Surgery, University of California, San Francisco, CA, USA
  • Jochen Tillein - Physiologisches Institut II, J.W. Goethe-University, Frankfurt a.M.
  • Ben H. Bonham - Department of Otolaryngology, Head and Neck Surgery, University of California, San Francisco, CA, USA

Deutsche Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie. 76. Jahresversammlung der Deutschen Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie e.V.. Erfurt, 04.-08.05.2005. Düsseldorf, Köln: German Medical Science; 2005. Doc05hno556

Die elektronische Version dieses Artikels ist vollständig und ist verfügbar unter: http://www.egms.de/de/meetings/hno2005/05hno031.shtml

Veröffentlicht: 22. September 2005

© 2005 Vollmer et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielf&aauml;ltigt, verbreitet und &oauml;ffentlich zug&aauml;nglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Using a forward masking paradigm the present study investigates the spectro-spatial interactions of combined electrical and acoustical stimulation (EAS) of the cochlea in inferior colliculus (IC) neurons.

Under general anesthesia normal hearing cats were implanted with a scala tympani electrode array. An earphone was sealed to the ipsilateral auditory meatus for acoustic stimulation. A 60-ms acoustic masker preceded a 20-ms electric probe (sinusoid). Masker and probe were systematically varied in intensity and frequency. Neural activity was recorded simultaneously at 16 sites along the tonotopic gradient of the contralateral IC using a multi-channel silicon probe.

At low intensities, electric probe frequencies activated primary IC locations that corresponded to the probe frequency. This activity was masked when the electric probe was preceded by acoustic stimuli of the same frequency.

At higher intensities, the electric probe activated secondary IC locations that corresponded to the cochlear site of the stimulating electrode(s). This activity was masked by acoustic frequencies that corresponded to the same cochlear site. Strength of masking was generally increased by increasing masker intensity.

The findings indicate that EAS produces complex spatial interactions in the central auditory system. The extent of these interactions is dependent on the intensities and spectral characteristics of both electric and acoustic stimulus components. The results also suggest that electric stimulation of the hearing cochlea evokes low-threshold acoustic-like electrophonic responses as well as high-threshold direct activation of the auditory nerve.

(Supported by NOHR, NIH N01 DC-2-1006, NIH N01 DC-3-1006 and MedEl)