Recognition of continuously read natural corpus

Preliminary results have been obtained with a system for recognizing continuously read sentences from a naturally-occurring corpus (Laser Patents), restricted to a 1000-word vocabulary. Our model of the task language has an entropy of about 4.8 bits/word and a perplexity of 21.11 words. Many new problems arise in recognition of a substantial natural corpus (compared to recognition of an artificially constrained language). Some techniques are described for treating these problems. On a test set consisting of 20 sentences having a total of 486 words, there was a word error rate of 33.1%.