Enhanced speechreading in deaf adults: can short-term training/practice close the gap for hearing adults?

This study investigated effects of short-term training/practice on group and individual differences in deaf and hearing speechreaders. In two experiments, participants speechread sentences with feedback during training and without feedback during testing, alternating 10 times over six sessions spanning up to 5 weeks. Testing used sentence sets balanced for expected mean performance. In each experiment, participants were adults who reported good speechreading and either normal hearing (n = 8) or severe to profound hearing impairments (n = 8). The experiments were replicates, except that in one participants received vibrotactile speech stimuli in addition to visible speech during training, testing whether vibrotactile speech enhances speechreading learning. Results showed that (a) training/practice did not alter the relative performance among individuals or groups; (b) significant learning occurred when training and testing were conducted with speechreading only (although the magnitude of the effect was small); and (c) there was evidence that the vibrotactile training depressed rather than raised speechreading scores over the training period.