Dealing with Loss of Synchronism in Multi-Band Continuous Speech Recognition Systems

Summary

In multi-band systems, the signal is decomposed into several frequency bands, which are processed separately. Then, the recombination part must compute a unique sentence from all these different solutions. The task is quite easy in isolated word recognition, each word ending at the same time, but it becomes more difficult in continuous speech recognition, where each band has a different segmentation. The problem here is to decide when the recombination should be done. Two major solutions have been tested: the first one introduces synchronism between the bands, and recombination is done when all the bands are synchronous. The second one leaves the sub-recognizers totally independent and tries to extract from their solutions a phonetic structure which will allow us to process the recombination part. We will briefly present an example of the first solution, then we will focus on the algorithm we have developed for the second one.