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Fourth International Symposium and Workshops: Objective Measures in Cochlear Implants

Medical University of Hannover

01.06. bis 04.06.2005, Hannover

Sudden Uncomfortable Loudness after Years of CI-Usage

Meeting Abstract

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  • corresponding author W.H. Döring - University Hospital Aachen, ENT-Dept.
  • A. Thauer - University Hospital Aachen, ENT-Dept.

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. Doc05omci070

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Veröffentlicht: 31. Mai 2005

© 2005 Döring et al.
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Normally, loudness and stimulation levels consolidate after some time of CI-usage and need only minor corrections. In some cases we could observe after one to four years of CI-usage that children suddenly (within a few days) complain about uncomfortable loudness and worse speech understanding. They turn down loudness and/ or sensitivity control and refuse to use their CI-system any longer. Most of those children were using SAS-strategy but there were some patients using HiRes- or ACE-strategy, too. Typical findings shall be demonstrated by the following case report.

Materials and Methods

A seven years old female child is using its HiFocus-CII/PSP-System (SAS) since three years with stable T- and M-Levels in the last 2 years. 3y-checkup revealed no need for program changes. Aided thresholds were about 30 to 40 dB, word score (without lipreading) came up to 70% at 75 dB (Göttinger Kindersprachtest I). Three months later, parents came with their child in our CI-Centre for immediate check-up about 3 days after she first showed severely reduced speech perception and complained about too loud sensations, even after turning down loudness setting to minimum (50%).


Checking M-Levels now revealed comfortable loudness for stimulation levels of about 35% to 45% of the former M-level settings. After building a new map comfortable loudness for speech could be achieved finally and speech perception could be restored. Electrode impedances remained stable within normal range before as well as after the incident. Actual NRI recordings showed considerably increased amplitudes of the neural response for medial and basal electrodes compared to those recordings taken before the sudden uncomfortable loudness.


Hypotheses of reasons explaining the findings described above should be discussed: First, technical causes had to be excluded. Second, the history of the children's health status (accidents, infections etc.) during the critical period had to be examined. In all 8 cases which we have seen up to now no unusual occurrences could be seen which could explain the observed sudden verstimulation. Hypotheses concerning imaginable physiological processes will be discussed with respect to the objective findings and comparable cases reported elsewhere.