“…In addition, in order to improve the distinguishability and robustness of acoustic features, reduce feature dimensions, and meet the actual needs of continuous speechrecognition systems, researchers have also proposed a variety of feature transformation methods [22][23][24][25][26][27][28][29][30][31][32]; the relevant research is shown in Table 1. LDA, Heteroscedastic Discriminant Analysis (HDA), Generalized Likelihood Ratio Discriminant Analysis (GLRDA), etc., can improve feature discrimination and reduce feature dimensions; Maximum Likelihood Linear Regression (MLLR), fMLLR, and Vocal Tract Length Normalization (VTLN) can eliminate speech information that has nothing to do with the recognition result, such as people or soundtrack, improving the robustness of features.…”