Most of the previous research on real-time captioning has focused on Automated Speech Recognition (ASR) (Saraclar et al., 2002;Cooke et al., 2001;Pražák et al., 2012).
experiments show that ASR systems are not robust enough to be applied for arbitrary speakers and in noisy environments (Wald, 2006b;Wald, 2006a;Bain et al., 2005;Bain et al., 2012;Cooke et al., 2001).