“…Three key points are important for building a DNN-based antispoofing system with generalization capabilities: (i) architecture, (ii) input features, and (iii) loss function. Multiple types of DNN architectures have been explored, such as feedforward DNN [16], convolutional neural network (CNN) [16], [17], recurrent neural network (RNN) [17], [18], gated recurrent neural network (GRCNN) [19], light convolutional gated recurrent neural network (LC-GRNN) [9], light convolutional neural network (LCNN) [20], central difference convolutional network (CDCN) [14], etc. Also, a wide range of features have been proposed to train these models, such as spectrogram [12], linear frequency cepstral coefficients (LFCC) [21], constant Q cepstral coefficients (CQCC) [22], raw speech samples [23], local similar pattern (LSP) features [15], signal-to-noise mask (SNM) [19] features, etc.…”