Lenore describes a situation that I have noticed, too. I asked her for permission to post her comment since I'm betting others have faced this issue and may have some good ideas for how to handle it. Here is what Lenore said:
<<One thought about Lexercise. On Isolator, I find that my students need time to process the information and make a decision. When the voice pipes in "Are ya there???" it's a bit disarming for them. I know they will get another chance at the word and I always assure them of that but in the moment it can be discouraging and often affects subsequent performance.