T. Abstract Automatic speech recognizers for dictation tasks at present work with vocabularies containing several hundred-thousand words. But even when using such an extensive vocabulary, it is still possible that necessary words are missing. Reasons for this are for example that the German language is rich in inflections and compound words.
Names form a another large group of words.
While most humans identify an unknown name without problems, this task is more difficult for a speech recognition system. Because the number of names is very high and there are always new creations, it is generally not possible to hold all names in the vocabulary of the speech recognizer in advance. In our case, this is English or Japanese. The detection is based on generic pronunciation and classes in the language model. If an unknown name is hypothesized by the speech recognizer a user dialog is initiated.