An abbreviated word recognition protocol based on item difficulty

The purpose of this investigation was to develop a test methodology that would identify those patients requiring a full 50 item word recognition test and allow abbreviated testing of patients who do not need a full 50 item word recognition test.

Listeners with normal hearing and listeners with sensorineural hearing loss were administered Auditec trade mark recordings of a 50 word NU-6 list(s). From these listener responses, error rates were determined for each word in the NU-6 word pool. The NU-6 lists were then reordered based on decreasing word difficulty and 10 word and 25 word screening tests were developed. The predictive power of the 10 word and 25 word screening tests was then determined based on the 95% critical difference values for word recognition scores. Clinical decision analysis (CDA) was used to assess how well the 10 word and 25 word screening tests predicted 50 word performance.

Data analyses showed: 1) the four NU-6 50 word lists were equivalent in item difficulty; 2) the four NU-6 10 word and 25 word lists were equivalent in item difficulty; and 3) the 10 word and 25 word screening tests have hit rate (HR) values of 93 to 100%, false alarm rate (FAR) values of 0 to 20% and A' values of 0.946 to 1.00 depending upon word configuration and pass criterion.

The four NU-6 10 word and 25 word screening tests differentiated listeners with impaired word recognition ability who required a full 50 word test from listeners with unimpaired word recognition ability who required only a 10 word or 25 word test.