Sound Quality and Performance

There is a wide variation among individuals in speech comprehension attained with the implant and no one can guarantee how well anyone will do with it.  There are many factors that go into determining how well someone does with an implant, many of which are not fully understood.  For this reason and others, the general consensus is to suggest that the sound quality with all the implants (Clarion, Nucleus, Med-El) are equally good, but this may not necessarily be the case.  Many doctors and audiologists are understandably reluctant to suggest that one implant may be better than another because a patient who does not do well with his/her implant may wind up blaming their recommendation for his poor performance.  Another informal way that some candidates try to evaluate the relative difference in sound quality with different implants is by asking friends or people they meet online; however, this approach is extremely problematic and can be misleading for several reasons (click here to learn more).

The best and most scientific way to evaluate relative differences in performance between implants is to examine the results of speech comprehension tests in controlled environments with all three implants.  These tests suggest that although performance and sound quality with the three implants is similar, they may not be identical.  As mentioned earlier, there is wide variation in terms of how well people do with any of the implants; however, average performance test results with each of the implants varies from one type to another.  The statistical variation among such test results is high, so it is difficult to make absolutely definitive conclusions as to whether one implant undoubtedly delivers superior performance over another as average scores might suggest.  Nevertheless, the results of such tests and independent studies suggest that--on average--the Clarion may be offering the highest level of performance, followed by the Nucleus, and trailed by the Med-El.  Below are the average results from clinical trials with each of the three implants:

Click here for a more extensive list of test results gathered with each of the implants, including sources for the data above. 

These are not the only tests to suggest a performance difference between the implants.  One small independent study concluded that even without its new high resolution capabilities, "the Clarion CII implant is able to produce unprecedented speech understanding" compared to other devices.  Another study, recently presented at the prestigious CIAP 2001 cochlear implant conference, tried to compensate for variations in individual characteristics among a few implant users and concluded that the Clarion offers superior performance over the Nucleus.  A third, independently-funded study that compared the Clarion CII HiRes to the Nucleus 3G concluded that "there are differences in performance between patients using the two implant systems" that are statistically significant, with the Clarion coming out on top.  To date, I have not seen any studies to contradict these findings.   This is not to say, of course, that any of the three implants aren't excellent in their own right, but it is also important to note that the existing evidence suggests that there may be slight differences in performance between them.

No one can guarantee how well anyone will do with their implant, but the evidence from speech tests suggest that--all other things being equal--some implants may be slightly better at delivering sound quality and speech comprehension than others.  Naturally, such benefits need to be weighed carefully against the many other advantages and disadvantages inherent to each device, such as battery life, MRI compatibility, and so on.

Please note the following about the results and conclusions on this page:

1. These results are for postlingual adults, but that one could argue that they can be used to draw general conclusions about relative performance in children and prelingual adults as well.  Results for children are hard to evaluate because a wide variety of different tests are used with different implants (making direct comparisons difficult) and because children of different ages do differently with their implants.

2. If more than one study was available to reflect an implant's performance on a given test, the average of all available tests was used.  For this reason, the numbers reflected on the chart above may not match best-case performance results that are advertised by the manufacturers.  Often, manufacturers report the results of the easiest tests available, so that they can market high numbers that make their implant sound impressive.  In order to truly evaluate performance across different implants, one needs to be sure that the same test and other factors are used in the comparison. 

3. Med-El's clinical trials were conducted using a slightly more challenging set of patients, so their average performance results may be slightly below what one might expect them to be using the same set of patients available to the other manufacturers; however, even accounting for such a difference, I think the relative rankings of performance across the devices probably stands.