The New York Times writes:
Mr. Chandratillakes solution does not reject any existing video search methods, but supplements them by transcribing the words uttered in a video, and searching them. This is an achievement: effective speech recognition is a nontrivial problem, in the language of computer scientists.
Blinkxs speech-recognition technology employs neural networks and machine learning using hidden Markov models, a method of statistical analysis in which the hidden characteristics of a thing are guessed from what is known.
Mr. Chandratillake calls this method contextual search, and he says it works so well because the meanings of the sounds of speech are unclear when considered by themselves. Consider the phrase recognize speech, he wrote in an e-mail message. Its phonemes (rek-un-nise-peach) are incredibly similar to those contained in the phrase wreck a nice beach. Our systems use our knowledge of which words typically appear in which contexts and everything we know about a given clip to improve our ability to guess what each phoneme actually means.