Psychometric Functions for Shortened Administrations of a Speech Recognition Approach Using Tri-Word Presentations and Phonemic Scoring

Abstract

Complete psychometric functions for phoneme and word recognition scores at 8 signal-to-noise ratios from -15 dB to 20 dB were generated for the first 10, 20, and 25, as well as all 50, three-word presentations of the Tri-Word or Computer Assisted Speech Recognition Assessment (CASRA) Test (Gelfand, 1998) based on the results of 12 normal-hearing young adult participants from the original study. The psychometric functions for both phoneme and word scores were very similar and essentially overlapping for all set sizes. Performance on the shortened tests accounted for 98.8% to 99.5% of the full (50-set) test variance with phoneme scoring, and 95.8% to 99.2% of the full test variance with word scoring. Shortening the tests accounted for little if any of the variance in the slopes of the functions. The psychometric functions for abbreviated versions of the Tri-Word speech recognition test using 10, 20, and 25 presentation sets were described and are comparable to those of the original 50-presentation approach for both phoneme and word scoring in healthy, normal-hearing, young adult participants.