“…For digital speech signals, there are a lot of research results in speech enhancement (Shima, Ahmad, & Babak, 2015;Ji & Danny, 2014;Mohamed & Pascal, 2014;Belinda & Kuldip, 2014;Seon & Hong, 2014) and speaker recognition (Shiha, Linb, Wanga, & Lina, 2011;Srikanth, 2014, pp. 137-145;Kawthar & Abderrahmane, 2014;Khan, Baig, & Youssef, 2010). However the speech content authentication schemes are rare.…”