Test-retest reliability of a distinctive feature difference test for hearing aid evaluation.

A short closed-set test of speech discrimination using consonants frequently confused by the hearing impaired and scored on the basis of distinctive features was developed and examined for reliability. In experiment I the Distinctive Feature Difference (DFD) Test and the CID W-22 Test were low-pass filtered and presented in a background of speech noise to 21 subjects with normal hearing. The DFD displayed superior test-retest reliability compared with the CID Auditory Test W-22 as indicated by small S.D.s, narrow range of individual test scores, and a lack of significant difference between means. In experiment II, the unfiltered DFD Test was presented in noise to 20 subjects with sensorineural hearing loss. Results similar to those of experiment I were obtained, indicating good test-retest reliability for the DFD Test with hearing-impaired subjects.