Estimating articulation scores

The ability of listeners to estimate articulation scores for lists of nonsense syllables was evaluated. Normal-hearing subjects were presented with lists of from 50 to 60 nonsense syllables that were degraded with various amounts of noise or filtering and were instructed to estimate consonant-correct scores for each condition. To provide a reference for estimating, subjects were shown the accurate orthographic representation of the syllable on a computer monitor to compare with the auditory presentation. The printed version was displayed either simultaneously with the auditory presentation or 500 ms after the offset of the syllable. Estimates were collected on two occasions to examine test-retest reliability, and actual percent-correct scores were obtained to check the accuracy of the estimates. Most subjects overestimated actual scores when the printed representation was provided simultaneously, but estimates were strikingly similar to actual scores when the printed representation was delayed. The delay appeared to prevent the printed representation from favorably biasing the reception of the syllable. The average of two or three estimates gave highly repeatable results for both visual displays. Crossover frequencies derived from the filtered-speech conditions were within the range reported in the literature. This supports the conclusion that subjects based their estimates on the recognition of speech sounds rather than other percepts associated with the speech-in-noise conditions such as loudness of the noise. The estimation procedure permits the collection of articulation scores in much less time than required by traditional test procedures.