Bi-Sep: A Multi-Resolution Cross-Domain Monaural Speech Separation Framework

In recent years, deep neural network (DNN)-based time-domain methods for monaural speech separation have substantially improved under an anechoic condition. However, the performance of these methods degrades when facing harsher conditions, such as noise or reverberation. Although adopting Short-Time Fourier Transform (STFT) for feature extraction of these neural methods helps stabilize the performance in non-anechoic situations, it inherently loses the fine-grained vision, which is one of the particularities of time-domain methods. Therefore, this study explores incorporating time and STFT-domain features to retain their beneficial characteristics. Furthermore, we leverage a Bi-Projection Fusion (BPF) mechanism to merge the information between two domains. To evaluate the effectiveness of our proposed method, we conduct experiments in an anechoic setting on the WSJ0-2mix dataset and noisy/reverberant settings on WHAM!/WHAMR! dataset. The experiment shows that with a cost of ignorable degradation on anechoic dataset, the proposed method manages to promote the performance of existing neural models when facing more complicated environments.