W-22 Word List Presented in Quiet and in Noise . Unpublished MS Thesis, University of Iowa. A common way to test whether a particular hearing aid is right for a patient is to play a tape on which 25 words are pronounced clearly but at low volume, and ask the patient to repeat the words as heard.
Different lists are available that are supposed to be of equal difficulty to understand correctly.
The lists have been calibrated using tests on normal subjects with minimal background noise. However, a major problem for those wearing hearing aids is that the aids amplify background noise as well as the desired sounds. They repeated the words and were scored correct or incorrect in their perception of the words. The order of list presentation was randomized.