Confidence ratings and awareness measures in word recognition testing

Abstract

Word recognition tests primarily use percent correct to measure performance. Additional information may be gained by analyzing awareness of accurate perceptions (AA), awareness of errant perceptions (AE), composite awareness (AC), and awareness symmetry (AS). Awareness measures were derived from subjects’ assignment of confidence ratings to a two-item multiple choice response test by designating ‘‘YES’’ or ‘‘NO’’ that their chosen response is accurate. Each response/confidence rating was categorized as a hit, miss, false alarm, or correct rejection. Awareness equations were: AA=hits/(hits+misses); AE=correct rejections/(correct rejections+false alarms); AC=SQRT (AA squared+AE squared); AS=0.707(AA−AE). Thus, AC is the vector to Cartesian coordinates AA, AE; AS is the distance of this point from a diagonal representing symmetrical awareness. Word recognition and awareness was investigated under two signal-to-noise ratios (3 and 6 dB). The Diagnostic Rhyme Test was presented at 50 dBHL to eight normal-hearing adults. Six replicates were obtained. Awareness measures provided additional performance information. Percent correct increased significantly as signal-to-noise ratio improved, but AE decreased and AS did not change significantly.