There are several programs available that claim to improve auditory processing. There is evidence that they encourage children to listen more carefully, but there is no evidence that we are aware of, that these programs increase their auditory processing capacity (the amount they can take in) faster than the normal developmental changes.
However, when children become more familiar with language, it is easier to remember.
When children concentrate better, either being less stressed and anxious, or with medication such as with Attention Deficit Disorder, or if they expect to be able to understand what is said, there can be an improvement in scores.
This capacity improves throughout childhood and continues to improve through adolescence although at a slightly slower rate.