“…Excitation features, such as voicing and fundamental frequency, are used in many speech processing applications and include, for example, speech coding, enhancement, noise estimation, automatic speech recognition in noisy conditions and tonal language speech recognition (Kaewtip et al, 2013;Kawahara et al, 2001;Lei et al, 2006;Ma et al, 2007;McAulay and Champion, 1990;Morales-Cordovilla et al, 2011a,b). Similarly, spectral envelope and formant features are used in a range of applications such as speech coding, synthesis, recognition and voice conversion (Hermansky, 1990;Kawahara et al, 2001Kawahara et al, , 2009Koriyama et al, 2014).…”