Written by William F. Carver, Ph.D., FAAA, FASHA, CCC(A)ret.
The problem of the amount of time required to thoroughly assess a client’s hearing capabilities is one which has plagued audiologists for many, many years. In an attempt to shorten the duration of a testing session, many audiologists utilize so-called “half lists.” This has been accomplished by either simply stopping the test after 25 words (from a 50 word list) or employing half lists that have been published.
As the reader may well know, both the W-22 and NU-6 have half list versions. Some of these lists have been ordered by difficulty, such that one can reduce the number of words to 10 in certain cases. While many deplore the use of half lists, their use has been ubiquitous. There are those who argue that 50 words are necessary to obtain reliable and valid results. That decision is up to the reader, but I recommend the Hurley version (see below).
Campbell’s half lists employ words from the W-22 lists. There are eight lists labeled M thru T. They are NOT ordered by difficulty. Beyond the initial research which produced these lists, I have not seen any further research on the lists. Consequently, I have no idea of their reliability or validity.
Auditec has two versions of NU-6 half lists, both of which purport to be ordered by difficulty. The first one, by Rose, is not recommended. (It was developed using Tillman’s NU-6 recording.) We have a more modern version by Hurley which has been rigorously researched using Auditec’s recording.* Both NU-6 versions use an interesting method for cutting test time significantly for patients with excellent word recognition ability. That is; the first 10 words in each list are the MOST difficult words in the list, so, if a patient misses any of these most difficult words, then the next 15 (total 25) words are presented. The Rose version stops there, while the recommendation for the Hurley version is that if more than three words are missed out of the 25, that the entire 50 word list be given. The Rose version will not allow that, since there are only 25 words in each of his (7) lists.
In addition, the Hurley version is available with a short interstimulus interval, which significantly reduces test time. (See our previous blog Short Interstimulus Interval.)
It must be obvious why we recommend the Hurley version for all word recognition testing. However, if one does not feel comfortable using half lists, then the entire 50 word list is there. On the other hand, if one is pressed for time, it is believed that the Hurley approach will produce reliable and valid information about a patient’s word recognition ability.
I should mention another test, the California Consonant Test (CCT). (It is not phonetically balanced, it employs 100 words per list (of two) which are heavily loaded with high pitched words.) It is a closed set test. The developers, Owens & Schubert, found that list 1 could be given as a half list. That is, they found that scores on each half were highly correlated and their results were reliable. This is not the case with list 2, however.
Hurley, R.M. & Sells, J.P. “An Abbreviated Word Recognition Protocol Based on Item Difficulty” Ear & Hearing, 24, 2003 (111-118)
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