Effects of error experience on learning to lower speech nasalance level

Purpose: This research aims to examine the effects of error experience when learning to speak with lowered nasalance level.
Method: A total of 45 typical speakers were instructed to learn to lower speech nasalance level in either an errorless (restricted possibility for committing errors) or an errorful (unrestricted possibility for committing errors) learning condition. The nasality level of the participants’ speech was measured by a nasometer and quantified by nasalance scores (in %). Errorless learners practiced producing speech with lowered nasalance level with a threshold nasalance score of 50% (the easiest target) at the beginning, which gradually decreased to a threshold of 10% (the most difficult target) at the end. The same set of threshold targets were presented to errorful learners, but in reverse order. Errors were defined by the proportion of speech with a nasalance score exceeding the threshold. Retention and transfer tests were administered.
Results: Errorless learners displayed fewer errors and lower mean nasalance scores than errorful learners during the acquisition phase. Furthermore, errorless learners achieved lower mean nasalance scores than errorful learners in the retention and transfer tests.
Conclusion: These results suggest that errorless learning is more effective than errorful learning, and that error experience has a detrimental effect on the acquisition of a novel speech motor task that requires minimization of the nasality level. Errorless learning may be a useful paradigm for the intervention and management of hypernasality in clinical settings where behavioral treatments are needed.