“…Statistical model Hidden Markov Model (HMM) is one of the most classical recognition methods for both automatic speech recognition and silent speech recognition, and has been widely implemented in relevant studies (Meltzner et al, 2011(Meltzner et al, , 2017(Meltzner et al, , 2018Kubo et al, 2013). With the development of high-performance computers and data acquisition techniques, machine learning algorithms such as the basic Feedforward Neural Networks (Jong and Phukpattaranont, 2019), Linear Discriminant Analysis (LDA) (Liu et al, 2020), Bayes network (Dobrucki et al, 2016), Random Forests (RF) (Rameau, 2020;Zhang et al, 2020), and Support Vector Machine (SVM) (Rameau, 2020) have been used for silent speech recognition. Recently, deep learning has achieved great success in pattern recognition tasks, among which Convolutional Neural Network (CNN) shows outstanding performance not only in image classification but also in speech recognition (Liu et al, 2018;Xiong et al, 2018;Rashno et al, 2019).…”