Cochlear implant programming: a global survey on the state of the art

Abstract

The programming of CIs is essential for good performance. However, no Good Clinical Practice guidelines exist. This paper reports on the results of an inventory of the current practice worldwide. A questionnaire was distributed to 47 CI centers. They follow 47600 recipients in 17 countries and 5 continents. The results were discussed during a debate. Sixty-two percent of the results were verified through individual interviews during the following months. Most centers (72%) participated in a cross-sectional study logging 5 consecutive fitting sessions in 5 different recipients. Data indicate that general practice starts with a single switch-on session, followed by three monthly sessions, three quarterly sessions, and then annual sessions, all containing one hour of programming and testing. The main focus lies on setting maximum and, to a lesser extent, minimum current levels per electrode. These levels are often determined on a few electrodes and then extrapolated. They are mainly based on subjective loudness perception by the CI user and, to a lesser extent, on pure tone and speech audiometry. Objective measures play a small role as indication of the global MAP profile. Other MAP parameters are rarely modified. Measurable targets are only defined for pure tone audiometry. Huge variation exists between centers on all aspects of the fitting practice.

Figures

Figure 1

Occurrence of MAP changes for the 4 brands (Cochlear, Med-El, AB, and Neurelec). (a) The left panel shows the frequency of changing the default settings at switch-on, as retrieved from the questionnaire and the interview; (b) the mid panel shows the distribution of the frequencies of changing the MAP parameters during the followup sessions, as retrieved from the questionnaire and the interview (Box and Whisker plots with the central dot depicting the median value, the box shows the quartile range and the whiskers show the range); (c) the right panel shows the occurrence of MAP changes as observed in the cross sectional snapshot.

Figure 2

Time analysis of the switch-on session, showing the number of sessions at daily intervals which are considered to constitute the switch-on procedure (pie chart at the left) and the time spent at the switch-on session (box and whisker plot at the right), both the total time and its breakdown into time spent at fitting and at testing. Time for counseling has not been enquired in this study. See caption of Figure 1 to interpret the box and whisker plots.

Figure 3

Alleged reasons for deactivating electrodes and the frequency they are reported to be really responsible for electrode deactivation in daily live.

Figure 4

Time analysis of the follow-on sessions during the first year after switch-on, showing the number of sessions (pie chart at the left) and the cumulative time spent at them (box and whisker plots at the right), both the total time and its breakdown into time spent at fitting and at testing. Time for counseling has not been enquired in this study. See caption of Figure 1 to interpret the box and whisker plots.

Figure 5

It shows the different outcome assessments which were enquired in the questionnaire together with the frequencies of the responses. The outcomes are grouped into 3 groups (subjective, objective, and psychoacoustic outcomes). The possible answers were (1) yes we assess this and use it to optimize the fitting (solid black and grey bars), (2) yes we assess this but for other reasons than steering the fitting, like for documentation or longitudinal followup (shaded bars), or (3) no we do not use to assess this (white bars). For the solid bars (assess and use it) a distinction was made into whether they have well defined targets to reach (black) or not (grey).

Figure 6

Histogram showing the frequency of the reported audiometric targets (dBHL) at different centers.