Bimodal sensor integration on the example of `speechreading´

It is shown how recognition performance in automated speech preception can be significantly improved by additional lipreading, so called speech-reading. It is shown on an extension of an existing state-of-the-art speech recognition system, a modular multi-state time-delay neural network (MS-TDNN). The acoustic and visual speech data are preclassified in two separate front-end phoneme TDNNs and combined to acoustic-visual hypotheses for the dynamic time warping algorithm. This is shown on a connected word recognition problem, the letter spelling task. With speech-reading the error rate can be reduced up to half of the error rate of pure acoustic recognition