8. The apparatus of claim 7 , wherein the at least one processor is programmed to generate an utterance validation score based, at least in part, on the text-independent audio sample received at the evaluation stage.
8. The apparatus of claim 7 , wherein the at least one processor is programmed to generate an utterance validation score based, at least in part, on the text-independent audio sample received at the evaluation stage. 9. The apparatus of claim 8 , wherein generating the utterance validation score comprises: performing automatic speech recognition on the text-independent audio sample received at the evaluation stage.