The goal of this research is developing a system that a rich facial animation can be used in communication is generated from only speech. Generally, a source of the generating facial animation is a camera. Using cameras as an input source, it causes limitations of the angle of view of the camera or problems that cannot be aware of the human face, depending on the orientation of the face. Therefore, it is reasonable for developing a system for generating a facial animation using only voice. In this study, we generate facial expressions from only speech using LSTM-RNN. Comparing 3 patterns of speech analysis data, we showed that the proposed method using A-weighting is effective for facial expression estimation.