Detecting the end of spellings using statistics on recognized letter sequences for spelled names recognition

This paper addresses the problem of end-of-speech detection for continuously spelled names. In order to reduce errors due to the premature detection of the end-of-speech resulting from a hesitation or from a long pause between some letters, we propose to detect prefixes of names. In this case, the recognition system will wait for extra speech in order to obtain a complete spelled name. The recognizer must also deal with incorrect data. Consequently a ternary decision is made when checking a recognized hypothesis: complete spelled name, prefix of a name or incorrect data which is rejected. The decision is made using three sequences of letters that decode the speech input under different syntactical constraints and the associated scores. We evaluated the approach with speech data collected from a vocal server in operation. About 83% of the prefixes are detected correctly, 2% are confused with complete spelled names and 15% are rejected