Issues with Using Personal Testimonies

When deciding whether or not to get an implant, or evaluating the differences between implants, it may be tempting to rely on the testimony offered by people on newsgroups or gatherings.  While such feedback can be extremely useful, there are several issues with relying on such testimonies as a primary source of information:

  1. There is a lot of variation in how well different people do with an implant.  Statistically speaking, one needs to gather feedback from at least 50 random people, at least, before the results can be considered statistically representative of what one might expect.  Even then, there's no saying that the feedback from a select group of individuals, such as those found on a newsgroup, is really representative of how well most people do with an implant.  For instance, newsgroups may be full of people who are there precisely because they are having problems with their implant, or conversely, because they are doing so well with it that they're excited to share their good fortune.  Either way, the feedback that such a group offers may be very unrepresentative of the average cochlear implant user.

  2. Cochlear implant technology is changing very rapidly, with new models coming out every few years.  Often people speaking to an implant recipient may not realize that that person's implant model is several years old and that the newer models offer additional features or capabilities that may not have been available at that time.  There are many components to a cochlear implant system, and one person's experience may not be completely relevant to another's if the components they will use are different.

  3. People's testimonials of how well they like their implant are extremely relative.  For instance, a person who does poorly with their implant but had even lower expectations to begin with, might say that they "love their implant."  Conversely, someone who does very well with their implant, but had higher expectations, might say that they "aren't very satisfied with it."  Similarly, some people report that they can "talk on the phone," while others report that "the phone is difficult," when in reality the first person may simply mean that they are only able to exchange basic information, whereas the second person may be able to carry long conversations but with some difficulty.  Listening to such testimonials, it would be easy to conclude that the first person's implant is better than the second, when in reality, the second person is getting much more out of his implant than the first.

  4. Some people on newsgroups may have vested or financial incentives to promote their brand of implant, which can seriously distort the perspective one gets of the different implants.  There have been several cases of overzealous advocates of one brand passing along factually incorrect information.  This is particularly a problem with paid advocates, who receive significant financial incentives ($3,000 a year) to promote one brand over another, yet intentionally don't reveal this to those that they advise.  Even when information isn't deliberately misrepresented, such paid advocates may be inherently prone to share or exaggerate success stories without sufficiently disclosing the negative experiences they may have had.  Currently, this appears to be a problem primarily with testimony from Nucleus users, as Cochlear Corporation is the only company that employs "paid advocates" who do not disclose their affiliation to the parent company.  This is unfortunate, because there are many satisfied Nucleus users, but it impossible to determine whether any testimony from a Nucleus user stems from genuine enthusiasm or from a hidden financial incentive to promote the brand.  There are at least a dozen or two paid advocates, if not more, dispersed throughout all the major newsgroups, so it is not difficult to see how their collective effort in favor of one brand can influence candidates' perceptions, especially when s/he is not aware that these individuals are paid for their promotional efforts.

For these reasons, I maintain that while individual testimonies are useful in evaluating cochlear implants, it is important to closely examine the results of FDA clinical trials.  Such measurements provide average results over large numbers of individuals (usually 50 or more), using standardized tests whose results can be compared against one another.  Click here for a comparison of such performance measurements across cochlear implants.

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