Paired comparison judgments of relative intelligibility in noise

Normal hearing and hearing impaired subjects listened alternately to continuous discourse processed by pairs of binaural hearing aids. In each case, they were asked to judge which pair of aids reproduced speech more intelligibly. Twenty-three pairs of aids competed in three elimination tournaments and one round-robin tournament. Speech discrimination tests obtained via each aid served as the criterion measure of the success of the judgments. The results were that the paired comparison procedure produced more reliable rankings than discrimination scores particularly when the difference between aids was small. Concerning validity, the normal hearing subjects identified the aids producing the best discrimination scores very well. Also, they applied confidence ratings to their judgements that were well related to the size of the performance difference between the aids. The hearing impaired subjects also performed well generally but on occasion individuals in this group chose aids that were clearly not best for them or the group.