Call analysis with classification using speech and non-speech features

This paper reports our recent development of a highly reliable call analysis technique that makes novel use of automatic speech recognition (ASR), speech utterance classification and non-speech features. The main ideas include the use the NGram filler model to improve the ASR accuracy on important words in a message, and the integration of recognized utterance with non-speech features such as utterance length, and the use of utterance classification technique to interpret the message and extract additional information. Experimental evaluation shows that the use of the utterance length, recognized text, and the classifier’s confidence measure reduces the classification error rate to 2.5% of the test sets.