Consonant similarity judgments by normal and hearing-impaired listeners.

This investigation attempted to identify listener strategies or perceptual modes that might be adopted by hearing-impaired listeners when making similarity judgments among pairs of speech sounds. Further, an attempt was made to describe the relationship between similarity judgments and auditory confusions for such listeners. Subjects provided similarity ratings and recognition responses to consonant pairs. The resulting similarity judgments were organized into a variety of similarity matrices and analyzed via multidimensional scaling and hierarchical clustering, as well as by traditional descriptive and interpretative statistics. The analyses of the similarity ratings between consonants showed that hearing-impaired listeners apply phonemic labels to the stimuli and base their ratings on these labels rather than on the unlabeled acoustic characteristics of the speech sounds. Analysis of the recognition data indicated that those consonants which are most confused are not necessarily the most conceptually similar to the listener.