[Is Flying or Diving risky after cochlear implantation? Examination in a pressure chamber]. / Ist Fliegen oder Tauchen riskant für CI-Träger? ­ Untersuchungen in einer Druckkammer.

OBJECTIVE: Complications after cochlear implantation are relatively rare but patients are asked to follow certain behavioral rules. Until now there is no evidence if pressure changes that occur during flying and diving are safe for patients after cochlear implantation. For example, no recommendation exists for SCUBA- diving activities. MATERIALS AND METHODS: In a hypo-/hyperbaric pressure chamber patients after cochlear implantation were exposed to a standardized profile of decompression and compression simulating a flight in a common airplane and a dive. Pre and after the exposure in the pressure chamber, ENT examination and a control of impedances of the cochlear implant were performed. Additionally, patients filled in a questionnaire about complaints they had experienced in the pressure chamber or after. RESULTS: A total of 11 subjects (17 ears with CI) were examined in the pressure chamber. 2/3 of the subjects stated that they had slight complaints during the examination. Only in one patient the measurement needed to be stopped due to pain. Seven patients showed a vascular injection of the malleus in ear microscopy. In none of the patients there was a subjective change in hearing after the examination. Objective measurements of the impedance did not show relevant changes. CONCLUSION: The exposure of cochlear implanted patients to overpressure and underpressure in a pressure chamber did not result in any significant deviation of the impedances, so that no further adjustment was necessary. Since there are no certified in vivo studies on pressure changes while diving and flying with a cochlear implant, further studies are required in order to be able to adequately advise CI patients about diving and flying.

Comparison of the Effects of Two Cochlear Implant Fine Structure Coding Strategies on Speech Perception.

Purpose This study aims to investigate the effect of upgrading from the fine structure processing (FSP) coding strategy to the novel fine structure strategy "FS4" in adults in adults with cochlear implants manufactured by MED-EL GmbH (Innsbruck, Austria). Method A crossover, double-blinded study was conducted for 12 weeks. Twelve adult participants were randomly assigned to two groups. During the first 6-week test interval, one group continued to use their everyday FSP strategy, whereas the other group was upgraded to the FS4 strategy. In the second 6-week interval, the two groups switched coding strategies. Speech perception was measured at the end of each test interval with the Oldenburg Sentence Test and the Göttingen Sentence Test. Participants completed the Speech, Spatial and Qualities of Hearing Scale at the end of each test interval and a simple preference test at the end of the study. Results There was no significant difference in speech perception test results obtained with the Oldenburg Sentence Test and the Göttingen Sentence Test, neither in quiet nor in noise. Participants' Speech, Spatial and Qualities of Hearing Scale self-evaluation and preference test results showed that the two coding strategies had similar effects on their hearing perception. No clear preference for either of the strategies was found. Conclusions Speech perception test results and the participants' level of satisfaction were similar for the two FS coding strategies. Despite differences in the presentation of temporal fine structure between FSP and FS4, a clear benefit of the newer FS4 strategy could not be shown.

Examination of Prosody and Timbre Perception in Adults With Cochlear Implants Comparing Different Fine Structure Coding Strategies.

PURPOSE: This study aimed to investigate whether adults with cochlear implants benefit from a change of fine structure (FS) coding strategies regarding the discrimination of prosodic speech cues, timbre cues, and the identification of natural instruments. The FS processing (FSP) coding strategy was compared to 2 settings of the FS4 strategy. METHOD: A longitudinal crossover, double-blinded study was conducted. This study consisted of 2 parts, with 14 participants in the first part and 12 participants in the second part. Each part lasted 3 months, in which participants were alternately fitted with either the established FSP strategy or 1 of the 2 newly developed FS4 settings. Participants had to complete an intonation identification test; a timbre discrimination test in which 1 of 2 isolated cues changed, either the spectral centroid or the spectral irregularity; and an instrument identification test. RESULTS: A significant effect was seen in the discrimination of spectral irregularity with 1 of the 2 FS4 settings. The improvement was seen in the FS4 setting in which the upper envelope channels had a low stimulation rate. This improvement was not seen with the FS4 setting that had a higher stimulation rate on the envelope channels. CONCLUSIONS: In general, the FSP strategy and the 2 settings of the FS4 strategy provided similar levels in the perception of prosody and timbre cues, as well as in the identification of instruments.

Effects of various electrode configurations on music perception, intonation and speaker gender identification.

Advances in speech coding strategies and electrode array designs for cochlear implants (CIs) predominantly aim at improving speech perception. Current efforts are also directed at transmitting appropriate cues of the fundamental frequency (F0) to the auditory nerve with respect to speech quality, prosody, and music perception. The aim of this study was to examine the effects of various electrode configurations and coding strategies on speech intonation identification, speaker gender identification, and music quality rating. In six MED-EL CI users electrodes were selectively deactivated in order to simulate different insertion depths and inter-electrode distances when using the high definition continuous interleaved sampling (HDCIS) and fine structure processing (FSP) speech coding strategies. Identification of intonation and speaker gender was determined and music quality rating was assessed. For intonation identification HDCIS was robust against the different electrode configurations, whereas fine structure processing showed significantly worse results when a short electrode depth was simulated. In contrast, speaker gender recognition was not affected by electrode configuration or speech coding strategy. Music quality rating was sensitive to electrode configuration. In conclusion, the three experiments revealed different outcomes, even though they all addressed the reception of F0 cues. Rapid changes in F0, as seen with intonation, were the most sensitive to electrode configurations and coding strategies. In contrast, electrode configurations and coding strategies did not show large effects when F0 information was available over a longer time period, as seen with speaker gender. Music quality relies on additional spectral cues other than F0, and was poorest when a shallow insertion was simulated.