Therapy for Auditory Processing Impairment in Aphasia: An evaluation of two approaches

Purpose: This study evaluated two forms of discrimination therapy for auditory processing impairment in aphasia. It aimed to determine whether therapy can improve speech perception and/or help participants use semantic information to compensate for their impairment. Changes in listening were also explored by recording the level of facilitation needed during therapy tasks. Finally the study examined the effect of therapy on an everyday listening activity: a telephone message task. Method: The study employed a repeated measures design. Eight participants received 12 sessions each of phonological and semantic-phonological therapy. Both programmes used minimal pair judgement tasks, but the latter embedded such tasks within a meaningful context, so encouraged the strategic use of semantic information (semantic bootstrapping). Experimental measures of auditory discrimination and comprehension were administered twice before therapy, once after each programme, and again six weeks later. The telephone message task was also administered at each time point. Test data were subjected to both group and individual analyses. Records of progress during therapy (i.e changes in support needed to carry out therapy tasks) were completed during treatment and analysed across the group. Results: Group analyses showed no significant changes in tests of word and nonword discrimination as a result of therapy. One comprehension task improved following therapy, but two did not. There was also no indication that therapy improved the discrimination of treated words, as assessed by a priming task. The facilitation scores indicated that participants needed less support during tasks as therapy progressed, possibly as a result of improved listening. There was a significant effect of time on the telephone message task. Across all tasks there were few individual gains. Conclusions: The results offer little evidence that therapy improved participants’ discrimination or semantic bootstrapping skills. Some changes in listening may have occurred, as indicated by the facilitation scores. Reasons for the null findings are discussed