US Patent 10332508 Confidence checking for speech processing and query answering

An automatic speech recognition (ASR) system uses recurrent neural network (RNN) encoding to create a feature vector corresponding to a word sequence ASR result where the feature vector incorporates data from different hierarchies (i.e., frame level, phone level, etc.) of the ASR processing. The feature vector may be used with a trained classifier to confirm that the ASR result was correct, or to otherwise assign a confidence score to the ASR results.