A series of questions and answers to help you debug responses from MRCP and chose the best parameter values.

About barge-in

This option, sometimes offered by IVR/bots, means that recognition is started when the robot starts talking. A a result recognition might be running for quite a long time in case the human user is waiting for the end of the robot's prompt. Use this feature with caution, as it might deteriorate the User Experience, as well as increase ASR costs (up to 3 times would not be a surprise).

Why do I get a No match with a result matching my parameters?

For example, I request digits?length=1, I say One, and I get a no-match despite having One as output of ASR.

First things first, please check the response header Completion-Reason, where the server explains its result.

In the described case, the message is most certainly "confidence too low". Confidence by default is equal to 0.5, and you can modify it. If response confidence is below this threshold, a no-match will be returned, even if as human we see that the result was in fact correct.